#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;
    
    ll j = W + 1;
    for (ll i = 0; i <= 2000000; i++){
        ll tate = min(H, LA * i);
        ll ka_sum = KA * i;
        
        while(j > 0){
            ll yoko = min(W, LB * (j - 1));
            ll kb_sum = KB * (j - 1);
            if (ka_sum + kb_sum < H * W - tate * yoko){
                break;
            }
            j--;
        }
        if (j != W + 1) ans = min(ans, i + j);
    }
    cout << ans << endl;
}