#include <bits/stdc++.h>
using namespace std;
long long mod(long long v, long long k, long long p) {
  long long res = 1;
  for (long long i = 0; i < 4; i++) res *= v, res %= p;
  res -= ((k * v) % p);
  if (res < 0) res += p;
  return res;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, p, k;
  cin >> n >> p >> k;
  long long Array[n];
  for (long long i = 0; i < n; i++) cin >> Array[i];
  long long B[n];
  for (long long i = 0; i < n; i++) B[i] = mod(Array[i], k, p);
  vector<long long> out;
  sort(B, B + n);
  long long cnt = 1;
  for (long long i = 0; i < n - 1; i++) {
    if (B[i + 1] != B[i] and cnt != 1)
      out.push_back(cnt), cnt = 1;
    else if (B[i + 1] == B[i])
      cnt++;
  }
  if (cnt != 1) out.push_back(cnt);
  long long sum = 0;
  for (long long i = 0; i < out.size(); i++)
    sum += ((out[i] * (out[i] - 1)) / 2);
  cout << sum << '\n';
  return 0;
}
