#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    ll h, w, la, lb, ka, kb; cin >> h >> w >> la >> lb >> ka >> kb;

    ll ans = INF;
    for(ll a=0; a<=(h+la-1)/la; a++){
        if(a*ka >= h*w){
            ans = min(ans, a);
        }else{
            if(min(a*la, h)*lb+kb==0) continue;
            ll b = (h*w-a*ka + min(a*la, h)*lb+kb-1)/(min(a*la, h)*lb+kb);

            if(min(a*la, h)*min(b*lb, w)+a*ka+b*ka >= h*w){
                ans = min(ans, a+b);
            }
        }
    }

    for(ll b=0; b<=(w+lb-1)/lb; b++){
        if(b*kb >= h*w){
            ans = min(ans, b);
        }else{
            if(min(b*lb, w)*la+ka==0) continue;
            ll a = (h*w-b*kb + min(b*lb, w)*la+ka-1)/(min(b*lb, w)*la+ka);
            if(min(a*la, h)*min(b*lb, w)+a*ka+b*ka >= h*w){
                ans = min(ans, a+b);
            }
        }
    }

    cout << ans << endl;
}