func_code_string: #include <bits/stdc++.h>   using namespace std;   long long a[300005];   long long s[300005];   int main() {     ios::sync_with_stdio(0);     cin.tie(NULL);     int n, p, k;     cin >> n >> p >> k;     for (int i = 1; i <= n; i++) {       cin >> a[i];       a[i] %= p;     }     map<long long, long long> cnt;     for (int i = 1; i <= n; i++) {       s[i] = a[i] * a[i] % p;       s[i] = s[i] * a[i] % p;       s[i] -= k;       s[i] = (s[i] % p + p) % p;       s[i] = s[i] * a[i] % p;       cnt[s[i]]++;     }     long long res = 0;     for (auto i : cnt) {       long long val = i.second * (i.second - 1) / 2;       res += val;     }     cout << res;     return 0;   }   