#include <bits/stdc++.h>
#include <algorithm>
#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 SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define VRSORT(v) sort(v.rbegin(), v.rend());
#define ll long long
#define pb(a) push_back(a)
#define INF 999999999
#define MOD (ll)(1e9+7)
#define MAX (ll)(1e5*2+200)
#define print(x) cout << x << endl;
#define length(arr) sizeof arr / sizeof arr[0];
#define printArr(arr) REP(i, (sizeof arr / sizeof arr[0])){print(arr[i])}
#define printVec(vec) REP(i, vec.size()){print(vec[i])}
#define VMAX(v) max_element(v.rbegin(), v.rend())

using namespace std;


int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    std::priority_queue<ll, vector<ll>, greater<ll>> q;
    std::priority_queue<ll> r;
    
    ll A, B, C, D;
    cin >> A >> B >> C >> D;
    
    ll ans = 0;
    int flag = 0;
    while(flag == 0){
        if(ans > D/(1+C) || ans > A || ans > B){
            flag = 1;
            ans -= 1;
        }else{
            ans += 1;
        }  
    }    
    
    print(ans);
    
    return 0;
}