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

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll A, B, C, D;
    cin >> A >> B >> C >> D;

    ll ans = 0;
    FOR(a, 1, A+1){
        ll need_meat = a * C;
        if(need_meat > B){
            break;
        }else{
            ll eat_sum = a + need_meat;
            if(eat_sum > D){
                break;
            }else{
                ans = a;
            }
        }
    }

    p(ans);
    
    return 0;
}