#include <bits/stdc++.h>
#define ll long long
using namespace std;


ll mod = 1e9+7;

ll gcd(ll a,ll b){
	if(b==0)return a;return gcd(b,a%b);
}
ll expo(ll base,ll pow){
    ll ans = 1;
    while(pow!=0){
        if(pow&1==1){ans = ans*base;}
        base *= base;pow/=2;}return ans;
}
ll inv(ll x){return expo(x,mod-2);}

ll dist[210][210];


int main(){
    //freopen("ip.txt", "rt", stdin);
    //freopen("op.txt", "wt", stdout);
    int p, d, m , s;
    cin >> p >> d >> m >> s;
    int ans = 0;
    while(s){
          if(p > m){
             if(s < p) break;
             s -= p;
             p -= d;
             ans++;
          }
          else{
             if(s < m) break;
             s -= m;
             ans++;
          }
    }
    cout << ans;
}