#include<bits/stdc++.h>
#define rep(i, x) for(ll i = 0; i < x; i++)
#define rep2(i, x) for(ll i = 1; i <= x; i++)
#define all(a) (a).begin(),(a).end()
using ll = long long;
using ld = long double;
using namespace std;
signed main() {
    ll a, b, c, d, ans = 0; cin >> a >> b >> c >> d;
	rep2(i, a) {
		if (i * c <= b && (i + i * c) <= d) { ans = i; }
	}
	cout << ans << endl;
	return 0;
}