func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = (int)2e9;   const double EPS = 1e-6;   const double PI = 3.1415926535;   const int MOD = 1000003;   int last[100000];   int main() {     int a, b, m, now, i = 2;     cin >> a >> b >> m >> now;     last[now] = 1;     while (1) {       now = (a * now + b) % m;       if (last[now]) {         cout << i - last[now];         return 0;       } else         last[now] = i++;     }   }   