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

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

long long pow_mod(long long x, long long n, long long p) {
	long long res = 1;
	while (n > 0) {
		if (n % 2 == 1) {
			res = (res * x) % p;
		}
		x = (x * x) % p;
		n /= 2;
	}
	return res;
}
long long inv_mod(long long x, long long p) { return pow_mod(x, p - 2, p); }
int main() {
	fast_io();
	int n, m, p, q;
	cin >> n >> m >> p >> q;
	for (; q--;) {
		int x, f;
		cin >> x >> f;
		if (x % p == 0) {
			cout << m << "\n";
			continue;
		}
		long long r = f * inv_mod(x, p) % p;
		// count x % p = r in [1, m]
		long long ans = m / p;
		if (m % p >= r) {
			ans++;
		}
		cout << ans << "\n";
	}
}