#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
using ll = int_fast64_t;
using ull = uint_fast64_t;

using mint = modint998244353;

constexpr ll INF = 1ll << 60;

template<typename T, typename D> void printelem(const T& container, const D& divide){
	for(const auto& i : container) cout << i << divide;
	cout << endl;
}
template<typename T> void printelem(const T& container) { printelem(container, ", "); }

int main(){
	//インプット
	ll N, M, P, Q;
	cin >> N >> M >> P >> Q;

	for(ll q = 0; q < Q; q++){
		ll x, f;
		cin >> x >> f;
		ll first = -1;
		for(ll i = x; i <= x*M; i += x){
			if(i % P == f){
				first = i;
				break;
			}
		}
		// ll ans = 0;
		// for(ll i = first; i <= x*M; i += x*P){
		// 	ans++;
		// }
		// if(first > 0) cout << ans << endl;
		// else cout << 0 << endl;
		if(first > 0) cout << (x*M-first)/(x*P) + 1 << endl;
		else cout << 0 << endl;
	}
	
	return 0;
}