#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using mint = atcoder::modint;
int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    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 << m << "\n";
            continue;
        }
        long y = (mint(x).inv() * f).val();
        if (m < y) cout << 0 << "\n";
        else {
            int t = (m - y) / p + 1;
            if (y == 0) t--;
            cout << t << "\n";
        }
    }
}