#include <iostream>
using namespace std;
typedef long long ll;

int main(){
    ll H, W, LA, LB, KA, KB;
    cin >> H >> W >> LA >> LB >> KA >> KB;

    ll ans = H + W + 1;
    
    //横パンチの回数を全探索
    for (ll i = 0; i <= H; i++){
        ll tate = min(H, LA * i);
        ll ka_sum = KA * i;

        //横パンチの回数を二分探索
        ll left = -1;
        ll right = W + 1;
        while(right - left > 1){
            ll center = (left + right) / 2;

            ll yoko = min(W, LB * center);
            ll kb_sum = KB * center;

            if (ka_sum + kb_sum >= H * W - tate * yoko){
                right = center;
            }
            else{
                left = center;
            }
        }
        if (right != W + 1) ans = min(ans, i + right);
    }
    cout << ans << endl;
}