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

typedef long long ll;
//typedef modint1000000007 mint;
const int MOD = 1000000007;
#define all(x) x.begin(), x.end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
const int inf = 1 << 30;
const ll INF = 1LL << 60;
const int dx[8] = {1, 0, -1, 0, -1, -1, 1, 1};
const int dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
template <class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template <class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }

/*
18 9

*/

int main(){
    int n, m, p, q;
    cin >> n >> m >> p >> q;

    while(q--){
        int x, f;
        cin >> x >> f;

        int fir = f / x;
        while(f % x != 0){
            f += p;
            if(f % x == 0) fir = f / x;
        }

        //cout << fir << endl;

        int ans = m / p;
        if(m % p >= fir) ans++;
        if(f == 0) ans--;

        cout << ans << endl;

    }

    return 0;
}