#include <iostream>
using namespace std;
using ll = long long;

int main()
{
    int a, b, c, d, ans = 0;
    cin >> a >> b >> c >> d;
    if (1 + c > d)
    {
        cout << 0 << endl;
    }
    else
    {
        while (a > 0 && b >= c)
        {
            ans++;
            b -= c;
            a--;
        }
        cout << ans << endl;
    }
}