#include <bits/stdc++.h>
using namespace std;;
#define ll long long
#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define INF 1<<30
#define LINF 1LL<<62
#define all(x) (x).begin(), (x).end()
const int MOD = 1000000007;
 
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
typedef pair<int, P> PP;
typedef pair<ll, LP> LPP;

int main(){
    int a,b,c,d; cin >> a >> b >> c >> d;
    int tmp = min(a,b/c);
    int ans = min(tmp, d/(c+1));
    cout << ans << endl;

}