#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
int main(){
  int i;
  ll h,w,la,lb,ka,kb,ma,mb,ans=2000000;
  cin >> h >> w >> la >> lb >> ka >> kb;
  ma=h/la+(h%la!=0 ? 1 : 0);
  mb=w/lb+(w%lb!=0 ? 1 : 0);
  for(i=0;i<=ma;i++){
    ll mini=-1,maxi=mb+1;
    while(abs(mini-maxi)>1){
      ll mid=(mini+maxi)/2;
      if(la*i*lb*mid+ka*i+kb*mid>=h*w) maxi=mid;
      else mini=mid;
    }
    if(la*i*lb*maxi+ka*i+kb*maxi>=h*w) ans=min(ans,i+maxi);
  }
  cout << ans << endl;
}