#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

ll INF=2e18;


int main() {
    ll H,W;
    cin>>H>>W;
    pair<ll,ll> L,K;
    cin>>L.first>>L.second;
    cin>>K.first>>K.second;

ll ans=INF;

if(K.first>0) {
    ans=min(ans,(H*W+K.first-1)/K.first);
}
if(K.second>0) {
    ans=min(ans,(H*W+K.second-1)/K.second);
}


for(ll i=1;i<=W;i++) {
    ll t=(i+L.second-1)/L.second;

if(H*W-i*H>t*K.second+K.first*((H+L.first-1)/L.first)) continue;


ll s=1,g=H;
while(s<g) {
    ll k=(s+g)/2;
    ll t2=(k+L.first-1)/L.first;

    ll count=t*K.second+t2*K.first;
    if(H*W-i*k<=count) g=k;
    else s=k+1;
}

ans=min(ans,t+(s+L.first-1)/L.first);
}


cout<<ans<<endl;


}