#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001



int main(){
	
	long long h,w,a,b,c,d;
	cin>>h>>w>>a>>b>>c>>d;
	long long ans = Inf64;
	for(long long i=0;i<=1000000;i++){
		long long ok = 1000000,ng = -1;
		while(ok-ng>1LL){
			long long mid  =(ok+ng)/2;
			long long rem = h*w;
			rem -= min(mid*b,w) * min(i*a,h);
			rem -= mid*d + i*c;
			if(rem<=0)ok = mid;
			else ng = mid;
			
		}
		ans = min(ans,i+ok);
	}
	cout<<ans<<endl;
	
	return 0;
}