#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
typedef pair<ll,ll> P;
#define Mod 1000000007
using VP = vector<P>; using VVP = vector<VP>;
using VI = vector<ll>; using VVI = vector<VI>; using VVVI = vector<VVI>;

int main(){
    ll i,j;
    ll a,b,c,d;
    cin>>a>>b>>c>>d;
    ll ans=0;
    while(b>=c){
        b-=c;
        d-=(c+1);
        if(d>=0) ans++;
    }
    cout<<min(a,ans)<<endl;
    
    return 0;
}