#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

#include <atcoder/modint>
using mint = atcoder::modint;

int find(int p, int t, int m) {
  int ok = 0, ng = m;
  while (ng - ok > 1) {
    ll mid = ((ll) ok + ng) / 2;
    (p * (mid - 1) + t <= m ? ok : ng) = mid;
  }
  return ok;
}

int main() {
  int n, m, p, q;
  cin >> n >> m >> p >> q;
  mint::set_mod(p);
  while (q--) {
    int x, f;
    cin >> x >> f;
    if (x % p == 0) {
      cout << (f == 0 ? m : 0) << endl;
    }
    else {
      mint a = mint(x).inv() * f;
      Debug(x, f, a.val());
      if (a.val() == 0) {
        cout << find(p, 0, m) - 1 << endl;
      }
      else {
        cout << find(p, a.val(), m) << endl;
      }
    }
  }
  return 0;
}