func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename S, typename T>   ostream& operator<<(ostream& out, pair<S, T> const& p) {     out <<  (  << p.first <<  ,   << p.second <<  ) ;     return out;   }   template <typename T>   ostream& operator<<(ostream& out, vector<T> const& v) {     long long l = v.size();     for (long long i = 0; i < l - 1; i++) out << v[i] <<    ;     if (l > 0) out << v[l - 1];     return out;   }   template <typename T>   void trace(const char* name, T&& arg1) {     cout << name <<   :   << arg1 <<   n ;   }   template <typename T, typename... Args>   void trace(const char* names, T&& arg1, Args&&... args) {     const char* comma = strchr(names + 1,  , );     cout.write(names, comma - names) <<   :   << arg1 <<   |  ;     trace(comma + 1, args...);   }   const long long N = 3e5 + 100;   long long MOD;   long long power(long long x, long long t) {     long long ans = 1;     while (t > 0) {       if (t & 1) ans = 1LL * ans * x % MOD;       x = 1LL * x * x % MOD;       t >>= 1;     }     return ans;   }   inline long long sub(long long a, long long b) {     a %= MOD;     b %= MOD;     a = ((a - b) % MOD + MOD) % MOD;     return a;   }   inline long long add(long long a, long long b) {     a %= MOD;     b %= MOD;     a = (a + b) % MOD;     return a;   }   inline long long mul(long long a, long long b) {     a %= MOD;     b %= MOD;     a = (a * b) % MOD;     return a;   }   inline long long inv(long long a) {     a = a % MOD;     a = power(a, MOD - 2);     return a;   }   long long a[N], n, k;   map<long long, long long> cnt;   int32_t main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     cin >> n >> MOD >> k;     for (long long i = 1; i <= n; i++) {       long long temp;       cin >> temp;       long long kk = power(temp, 4);       long long k2 = mul(k, temp);       kk = sub(kk, k2);       cnt[kk]++;     }     long long ans = 0;     auto c2 = [](long long a) -> long long { return ((a * (a - 1)) / 2); };     for (auto i : cnt) {       ans += c2(i.second);     }     cout << ans <<   n ;   }   