#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stdio.h>
using namespace std;
#define int long long
int MOD = 1000000007;
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int A, B, C, D;
	cin >> A >> B >> C >> D;
	int res = 0;
	while (true) {
		if (A >= 1 && B >= C && D >= 1 + C) {
			A--;
			B -= C;
			D -= 1 + C;
			res++;
		}
		else {
			break;
		}
	}


	cout << res << endl;
}