diff --git a/src/poseidon_printcontract.js b/src/poseidon_printcontract.js
index 04b5cce..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(5));
+const nInputs = Number(process.argv[2]);
+
+console.log(nInputs);
+
+console.log(poseidonGenContract.createCode(nInputs));