#include <iostream>

using namespace std;

int main(){
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    for(int i = a; i >= 0; i--){
        if(i * c <= b && i * (c + 1) <= d){
            cout << i << "\n";
            return 0;
        }
    }
    return 0;
}