#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define rep(i, n) for (int i = 0; i < n; i++)
#define INF (1LL << 60)
#define all(v) (v).begin(), (v).end()

template <class T>
void chmin(T &a, T b) {
    if (a > b) a = b;
}

template <class T>
void chmax(T &a, T b) {
    if (a < b) a = b;
}
long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

// a^-1
long long modinv(long long a, long long m) {
    long long b = m, u = 1, v = 0;
    while (b) {
        long long t = a / b;
        a -= t * b;
        swap(a, b);
        u -= t * v;
        swap(u, v);
    }
    u %= m;
    if (u < 0) u += m;
    return u;
}

int main() {
    ll N, M, P, Q;
    cin >> N >> M >> P >> Q;
    vector<ll> x(Q), f(Q);

    rep(i, Q) {
        cin >> x[i] >> f[i];
        ll ans = 0;
        ll tx = f[i] * modinv(x[i], P) % P;
        if (tx == 0) tx = P;
        ans = M / P;
        if (M % P >= tx) ans++;
        cout << ans << endl;
    }
}