func main[] : I64
    let out: I64 = 0

    for a in 500:1000
        for b in 500:1000
            if a * b > out
                let s: String = I64.to_string(a * b)
                let s_rev: String = strrev(s)
                if strcmp(s, s_rev) == 0
                    out = a * b
                free(s)
                free(s_rev)
    print_i64(out)