#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;


int main(){
    using M = atcoder::modint;
    i64 N, K, P, Q; cin >> N >> K >> P >> Q;
    i64 off = K / P;
    K %= P;
    M::set_mod(P);
    rep(q,Q){
        i64 x, f; cin >> x >> f;
        i64 ans = off;
        if((M(f) * M(x).inv() - 1).val() < K) ans++;
        cout << ans << '\n';
    }
    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;