// g++ 1.cpp -std=c++17 -O2 -I .
#include <bits/stdc++.h>
using namespace std;

#include <atcoder/all>
using namespace atcoder;

using ll = long long;
using ld = long double;
 
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vld = vector<ld>;
using vvld = vector<vld>;
using vst = vector<string>;
using vvst = vector<vst>;
 
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define pq_big(T) priority_queue<T,vector<T>,less<T>>
#define pq_small(T) priority_queue<T,vector<T>,greater<T>>
#define all(a) a.begin(),a.end()
#define rep(i,start,end) for(ll i=start;i<(ll)(end);i++)
#define per(i,start,end) for(ll i=start;i>=(ll)(end);i--)
#define uniq(a) sort(all(a));a.erase(unique(all(a)),a.end())

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  ll n,m,p,q;cin>>n>>m>>p>>q;
  while(q--){
    ll x,f;cin>>x>>f;
    // y = f / x
    f*=inv_mod(x,p);
    f%=p;
    ll m2=m%p;
    ll ans=m/p;
    if(1<=f&&f<=m2)ans++;
    cout<<ans<<endl;
  }
}