#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define int long long
using namespace std;
typedef pair<int, int> P;
const int mod = 1000000007;
const int INF = 1e18;

signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int a, b, c, d;
	cin >> a >> b >> c >> d;
	int ans = 0;
	rep(i, 0, a + 1){
		int niku = c * i;
		if(niku + i <= d && niku <= b){
			ans = i;
		}
	}
	cout << ans << endl;
}