#include <iostream>
#include <cassert>
using namespace std;
typedef long long ll;
ll A,B,C,D,inf = 100;
int main(){
	cin >> A >> B >> C >> D;
	assert(1<=A && A<=inf);
	assert(1<=B && B<=inf);
	assert(1<=C && C<=inf);
	assert(1<=D && D<=inf);
	cout << min(D/(C+1),min(B/C,A)) << endl;
}