#include<bits/stdc++.h>
using namespace std;
int node(int n,int m,int maxx,int minn){
	int ans=0;
	while((n>=maxx&&m>=minn)||(n>=minn&&m>=maxx)){
		int npp=0;
		if(n>m){
			npp=n/2/maxx;
			n-=npp*maxx;
			m-=npp*minn;
		}else if(n<m){
			npp=m/2/maxx;
			n-=npp*minn;
			m-=npp*maxx;
		}else {
			npp=n/2/maxx;
			n-=npp*maxx;
			m-=npp*minn;
		}
		ans+=npp;
	}
	return ans;
}
int main( ){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n,m,a,b;
	cin>>n>>m>>a>>b;
	int maxx=max(a,b);
	int minn=min(a,b);
	cout<<node(n,m,maxx,minn)<<'\n';
	return 0;
}

TLE:1 3 6 7 8 10 15 18 19 20 WA:2 13 14 16 17 AC:4 5 9 11 12