diff --git a/src/evmasm.js b/src/evmasm.js
index 8bf223f..ab7f830 100644
--- a/src/evmasm.js
+++ b/src/evmasm.js
@@ -154,6 +154,17 @@ class Contract {
     }
 
     push(data) {
+        if (typeof data === "number") {
+            let isNeg;
+            if (data<0) {
+                isNeg = true;
+                data = -data;
+            }
+            data = data.toString(16);
+            if (data.length % 2 == 1) data = "0" + data;
+            data = "0x" + data;
+            if (isNeg) data = "-"+data;
+        }
         const d = Web3Utils.hexToBytes(Web3Utils.toHex(data));
         if (d.length == 0 || d.length > 32) {
             throw new Error("Assertion failed");
diff --git a/src/poseidon.js b/src/poseidon.js
index e349fe1..db1c706 100644
--- a/src/poseidon.js
+++ b/src/poseidon.js
@@ -47,4 +47,3 @@ function poseidon(inputs) {
 }
 
 module.exports = poseidon;
-module.exports.F = F;
\ No newline at end of file
diff --git a/src/poseidon_gencontract.js b/src/poseidon_gencontract.js
index f482aec..c714305 100644
--- a/src/poseidon_gencontract.js
+++ b/src/poseidon_gencontract.js
@@ -2,14 +2,13 @@
 // License: LGPL-3.0+
 //
 
-const Poseidon = require("./poseidon.js");
-
 const Contract = require("./evmasm");
+const { unstringifyBigInts } = require("ffjavascript").utils;
 
-const SEED = "poseidon";
-const NROUNDSF = 8;
-const NROUNDSP = 57;
-const T = 6;
+const { C:K, M } = unstringifyBigInts(require("./poseidon_constants.json"));
+
+const N_ROUNDS_F = 8;
+const N_ROUNDS_P = [56, 57, 56, 60, 60, 63, 64, 63];
 
 function toHex256(a) {
     let S = a.toString(16);
@@ -17,38 +16,34 @@ function toHex256(a) {
     return "0x" + S;
 }
 
-function createCode(t, nRoundsF, nRoundsP, seed) {
-    if (typeof seed === "undefined") seed = SEED;
-    if (typeof nRoundsF === "undefined") nRoundsF = NROUNDSF;
-    if (typeof nRoundsP === "undefined") nRoundsP = NROUNDSP;
-    if (typeof t === "undefined") t = T;
+function createCode(nInputs) {
 
-    const K = Poseidon.getConstants(t, seed, nRoundsP + nRoundsF);
-    const M = Poseidon.getMatrix(t, seed, nRoundsP + nRoundsF);
+    if (( nInputs<1) || (nInputs>8)) throw new Error("Invalid number of inputs. Must be 1<=nInputs<=8");
+    const t = nInputs + 1;
+    const nRoundsF = N_ROUNDS_F;
+    const nRoundsP = N_ROUNDS_P[t - 2];
 
     const C = new Contract();
 
     function saveM() {
         for (let i=0; i<t; i++) {
             for (let j=0; j<t; j++) {
-                C.push(toHex256(M[i][j]));
+                C.push(toHex256(M[t-2][j][i]));
                 C.push((1+i*t+j)*32);
                 C.mstore();
             }
         }
     }
 
-    function ark(r) {
-        C.push(toHex256(K[r])); // K, st, q
+    function ark(r) {   // st, q
         for (let i=0; i<t; i++) {
-            C.dup(1+t); // q, K, st, q
-            C.dup(1);   // K, q, K, st, q
-            C.dup(3+i); // st[i], K, q, K, st, q
-            C.addmod(); // newSt[i], K, st, q
-            C.swap(2 + i); // xx, K, st, q
+            C.dup(t); // q, st, q
+            C.push(toHex256(K[t-2][r*t+i]));  // K, q, st, q
+            C.dup(2+i); // st[i], K, q, st, q
+            C.addmod(); // newSt[i], st, q
+            C.swap(1 + i); // xx, st, q
             C.pop();
         }
-        C.pop();
     }
 
     function sigma(p) {
@@ -115,17 +110,17 @@ function createCode(t, nRoundsF, nRoundsP, seed) {
 
     C.push("0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001");  // q
 
-    // Load 6 values from the call data.
+    // Load t values from the call data.
     // The function has a single array param param
     // [Selector (4)] [Pointer (32)][Length (32)] [data1 (32)] ....
-    // We ignore the pointer and the length and just load 6 values to the state
-    // (Stack positions 0-5) If the array is shorter, we just set zeros.
+    // We ignore the pointer and the length and just load t values to the state
+    // (Stack positions 0-{t-1}) If the array is shorter, we just set zeros.
     for (let i=0; i<t; i++) {
         C.push(0x44+(0x20*(5-i)));
         C.calldataload();
     }
 
-    for (let i=0; i<nRoundsF+nRoundsP; i++) {
+    for (let i=0; i<nRoundsF+nRoundsP-1; i++) {
         ark(i);
         if ((i<nRoundsF/2) || (i>=nRoundsP+nRoundsF/2)) {
             for (let j=0; j<t; j++) {
@@ -142,6 +137,13 @@ function createCode(t, nRoundsF, nRoundsP, seed) {
         C.label(strLabel);
     }
 
+    C.push(toHex256(K[t-2][(nRoundsF+nRoundsP-1)*t]));  // K, st, q
+    C.dup(t+1); // q, K, st, q
+    C.swap(2);  // st[0], K, q, st\st[0]
+    C.addmod();  // st q
+
+    sigma(0);
+
     C.push("0x00");
     C.mstore();     // Save it to pos 0;
     C.push("0x20");
diff --git a/src/poseidon_printconstants.js b/src/poseidon_printconstants.js
deleted file mode 100644
index 1825798..0000000
--- a/src/poseidon_printconstants.js
+++ /dev/null
@@ -1,16 +0,0 @@
-
-
-const Poseidon = require("./poseidon.js");
-
-const C = Poseidon.getConstants();
-
-let S = "[\n";
-
-for (let i=0; i<C.length; i++) {
-    S = S + "    " + C[i].toString();
-    if (i<C.length-1) S = S + ",";
-    S = S + "\n";
-}
-S=S+ "]\n";
-
-console.log(S);
diff --git a/src/poseidon_printcontract.js b/src/poseidon_printcontract.js
index 61c6168..0ae977d 100644
--- a/src/poseidon_printcontract.js
+++ b/src/poseidon_printcontract.js
@@ -1,5 +1,13 @@
 const poseidonGenContract = require("./poseidon_gencontract");
 
+if (process.argv.length != 3) {
+    console.log("Usage: node poseidon_gencontract.js [numberOfInputs]");
+    process.exit(1);
+}
 
-console.log(poseidonGenContract.createCode(6, 8, 57));
+const nInputs = Number(process.argv[2]);
+
+console.log(nInputs);
+
+console.log(poseidonGenContract.createCode(nInputs));
 
diff --git a/src/smt_hashes_poseidon.js b/src/smt_hashes_poseidon.js
index 2b38192..67a080e 100644
--- a/src/smt_hashes_poseidon.js
+++ b/src/smt_hashes_poseidon.js
@@ -1,6 +1,8 @@
 const poseidon = require("./poseidon");
 const bigInt = require("snarkjs").bigInt;
 
+//const F = new ZqField(Scalar.fromString("21888242871839275222246405745257275088548364400416034343698204186575808495617"));
+
 exports.hash0 = function (left, right) {
     return poseidon([left, right]);
 };
@@ -9,4 +11,4 @@ exports.hash1 = function(key, value) {
     return poseidon([key, value, bigInt.one]);
 };
 
-exports.F = poseidon.F;
+//exports.F = poseidon.F;
diff --git a/test/eddsa_js.js b/test/eddsa_js.js
index 2771306..bea64ad 100644
--- a/test/eddsa_js.js
+++ b/test/eddsa_js.js
@@ -68,12 +68,12 @@ describe("EdDSA js test", function () {
         assert.equal(signature.R8[1].toString(),
             "15383486972088797283337779941324724402501462225528836549661220478783371668959");
         assert.equal(signature.S.toString(),
-            "248298168863866362217836334079793350221620631973732197668910946177382043688");
+            "1398758333392199195742243841591064350253744445503462896781493968760929513778");
 
         const pSignature = eddsa.packSignature(signature);
         assert.equal(pSignature.toString("hex"), ""+
             "dfedb4315d3f2eb4de2d3c510d7a987dcab67089c8ace06308827bf5bcbe02a2"+
-            "28506bce274aa1b3f7e7c2fd7e4fe09bff8f9aa37a42def7994e98f322888c00");
+            "32f16b0f2f4c4e1169aa59685637e1429b6581a9531d058d65f4ab224eab1703");
 
         const uSignature = eddsa.unpackSignature(pSignature);
         assert(eddsa.verifyPoseidon(msg, uSignature, pubKey));
diff --git a/test/poseidoncontract.js b/test/poseidoncontract.js
index 12c2c82..0ca7f15 100644
--- a/test/poseidoncontract.js
+++ b/test/poseidoncontract.js
@@ -26,13 +26,13 @@ describe("Poseidon Smart contract test", function () {
         poseidon2 = await C.deploy({
             data: poseidonGenContract.createCode(2)
         }).send({
-            gas: 2500000,
+            gas: 5000000,
             from: accounts[0]
         });
         poseidon4 = await C.deploy({
             data: poseidonGenContract.createCode(4)
         }).send({
-            gas: 2500000,
+            gas: 5000000,
             from: accounts[0]
         });
     });