#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 998244353;
// constexpr int MOD = 1000000007;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

long long mod_inv(long long a, const int m) {
  if ((a %= m) < 0) a += m;
  if (std::gcd(a, m) != 1) return -1;
  long long x = 1;
  for (long long b = m, u = 0; b > 0;) {
    const long long q = a / b;
    std::swap(a -= q * b, b);
    std::swap(x -= q * u, u);
  }
  x %= m;
  return x < 0 ? x + m : x;
}

int main() {
  int n, m, p, q; cin >> n >> m >> p >> q;
  while (q--) {
    int x, f; cin >> x >> f;
    if (x % p == 0) {
      cout << (f == 0 ? m : 0) << '\n';
    } else {
      const ll y = f * mod_inv(x, p) % p;
      cout << m / p + (y == 0 ? 0 : y <= m % p) << '\n';
    }
  }
  return 0;
}