#include <iostream>
using namespace std;



struct ModInt{
  int n;
  int mod;
  ModInt(int mod, int n_):mod(mod), n(n_ >= 0 ? n_%mod : mod - ((-n_)%mod) ){}

  ModInt &operator+=(const ModInt &p){
    if((n+=p.n) >= mod)n-=mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p){
    n+=mod-p.n;
    if(n >= mod)n-=mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p){
    n = (int) ((1LL*n*p.n)%mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p){
    *this *= p.inverse();
    return *this;
  }
  ModInt operator-() const {return ModInt(mod, -n);}
  ModInt operator+(const ModInt &p) const {return ModInt(*this) += p;}
  ModInt operator-(const ModInt &p) const {return ModInt(*this) -= p;}
  ModInt operator*(const ModInt &p) const {return ModInt(*this) *= p;}
  ModInt operator/(const ModInt &p) const {return ModInt(*this) /= p;}

  bool operator==(const ModInt &p) const {return n==p.n;}
	bool operator<(const ModInt &p) const {return n<p.n;}
	bool operator>(const ModInt &p) const {return n>p.n;}
	bool operator>=(const ModInt &p) const {return n>=p.n;}
	bool operator<=(const ModInt &p) const {return n<=p.n;}
  bool operator!=(const ModInt &p) const {return n!=p.n;}

  ModInt inverse() const {
    int a = n,b = mod,u = 1,v = 0;
    while(b){
      int t = a/b;
      a -= t*b; swap(a,b);
      u -= t*v; swap(u,v);
    }
    ModInt ret(mod, u);
    return ret;
  }

  ModInt pow(int64_t z) const {
    ModInt ret(mod, 1),mul(mod, n);
    while(z > 0){
      if(z & 1) ret *= mul;
      mul *= mul;
      z >>= 1;
    }
    return ret;
  }

  int toInt(){
    return n;
  }

  friend ostream &operator<<(ostream &os, const ModInt &p){
    return os << p.n;
  }
};

int main(){
  long long n,m,p,q;cin>>n>>m>>p>>q;
  for(int i = 0; q > i; i++){
    long long X,F;cin>>X>>F;
    ModInt x(p,X),f(p,F);
    if(x.toInt() == 0){
      if(f.toInt() == 0)cout << m << endl;
      else cout << 0 << endl;
    }else{
      (f/x).toInt();
      cout << m/p + ((f/x).toInt() <= (m%p) && f.toInt() != 0) << endl;
    }

  }
}