#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000000000000


int main(){
	
	int A,B,C,D;
	cin>>A>>B>>C>>D;
	
	int ans = 0;
	
	rep(i,1000){
		if(A<i)continue;
		if(B<i*C)continue;
		if(i+C*i>D)continue;
		ans = i;
	}
	
	cout<<ans<<endl;
	
    return 0;
}