# bug: Leading zeros in input arguments silently accepted

[chamitro]

Bug Report

Cairo version: 2.16.1 (scarb 2.16.1)

Current behavior:

Input arguments with leading zeros (e.g., 007, 00100) are silently accepted and parsed as their decimal value. While this produces correct results, it indicates the input parser accepts non-canonical number representations without warning.

Expected behavior:

Either:

1. Accept with canonical parsing (current behavior is functionally correct)
2. Warn: Warning: input '007' has leading zeros, interpreting as 7

Steps to reproduce:

#[executable]
fn main(a: felt252) -> felt252 {
    a + 1
}

scarb execute --arguments="007" --print-program-output
# Output: 8 (007 parsed as 7, 7+1=8, no warning)

scarb execute --arguments="00100" --print-program-output
# Output: 101 (00100 parsed as 100)

Related code:

#[executable]
fn main(a: felt252) -> felt252 {
    a + 1
}

Other information:

Input	Circom	Noir	Cairo	Leo
007	Accepts (7)	Accepts (7)	❌ Accepts (7)	Rejects
00100	Accepts (100)	Accepts (100)	❌ Accepts (100)	Rejects

[chamitro]

@orizi @mkaput