#include<bits/stdc++.h>
using namespace std;
using ll=long long;

ll modinv(ll a,ll m){
  ll b=m,u=1,v=0;
  while(b){
    ll t=a/b;
    a-=t*b;
    swap(a,b);
    u-=t*v;
    swap(u,v);
  }
  u%=m;
  if(u<0){
    u+=m;
  }
  return u;
}

int main(){
  ll n,m,p,q;
  cin>>n>>m>>p>>q;
  while(q--){
    ll x,f;
    cin>>x>>f;
    x%=p;
    ll inv=modinv(x,p);
    ll y=f*inv%p;
    if(y>m){
      cout<<0<<endl;
    }else{
      ll cnt=(m-y)/p+1;
      if(y==0){
        cnt--;
      }
      cout<<cnt<<endl;
    }
  }
}