#include <bits/stdc++.h>
using namespace std;
#include <atcoder/math>
using namespace atcoder;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    ll n,m,p,q;
    cin >> n >> m >> p >> q;
    rep(i,q){
        ll x,f,ans;
        cin >> x >> f;
        if(x%p){
            ll r = crt({f,0}, {p,x}).first;
            if(r==0) r = p*x;
            ans = (m - (r/x-1) + p - 1) / p;
        }else{
            ans = (f?0:m);
        }
        cout << ans << '\n';
    }
    return 0;
}