// 

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define rep(i, n) for (int i=0; i<(int)(n); ++(i))
#define rep3(i, m, n) for (int i=(m); (i)<(int)(n); ++(i))
#define repr(i, n) for (int i=(int)(n)-1; (i)>=0; --(i))
#define rep3r(i, m, n) for (int i=(int)(n)-1; (i)>=(int)(m); --(i))
#define all(x) (x).begin(), (x).end()

const int INF = (int)(1e9);

int main() {
    int h, w, la, lb;
    ll ka, kb;
    cin >> h >> w >> la >> lb >> ka >> kb;
    int amx = (h+la-1) / la, bmx = (w+lb-1) / lb, res = INF;
    rep(acnt, amx+1) {
        ll alen = min(h, acnt*la), adda = acnt * ka;
        int lval = -1, rval = bmx + 1;
        while (rval-lval > 1) {
            int bcnt = rval - (rval-lval) / 2;
            ll blen = min(w, bcnt*lb), addb = bcnt * kb;
            if (alen*blen+adda+addb < (ll)h*w) lval = bcnt;
            else rval = bcnt;
        }
        if (rval <= bmx) res = min(res, acnt+rval);
    }
    cout << res << endl;
    return 0;
}