#include "bits/stdc++.h"

using namespace std;

#define int long long
#define ll long long
typedef pair<int, int> P;
#define mod 1000000007
#define INF (1LL<<60)

#define rep(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define YES cout << "YES" << endl;
#define Yes cout << "Yes" << endl;
#define NO cout << "NO" << endl;
#define No cout << "No" << endl;


signed main(){

	int A,B,C,D;
	cin >> A >> B >> C >> D;
	int i;
	for (i = 1; i <= A; i++){
		if (i*C > B) break;
		if (i + i*C > D)break;
	}

	cout << i-1 << endl;

	return 0;
}