func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int p, x, ans = 0;     bool b;     cin >> p;     for (int i = 1; i < p; i++) {       b = 1;       x = 1;       for (int j = 1; j < p - 1; j++) {         x = (x * i) % p;         if ((x - 1) % p == 0) b = 0;       }       if (((x * i) - 1) % p != 0) b = 0;       if (b) ans++;     }     cout << ans << endl;     return 0;   }   