// 

import java.util.*;

public class Main_sol2 {
    private static final int INF = (int)(1e9);
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int h = sc.nextInt(), w = sc.nextInt(), la = sc.nextInt(), lb = sc.nextInt();
        long ka = sc.nextLong(), kb = sc.nextLong();
        sc.close();
        int amx = (h+la-1) / la, bmx = (w+lb-1) / lb, res = INF;
        for (int acnt=0; acnt<=amx; ++acnt) {
            long alen = Math.min(h, acnt*la), adda = acnt * ka;
            int lval = -1, rval = bmx + 1;
            while (rval-lval > 1) {
                int cval = rval - (rval-lval) / 2;
                long blen = Math.min(w, cval*lb), addb = cval * kb;
                if (alen*blen+adda+addb < (long)h*w) lval = cval;
                else rval = cval;
            }
            if (rval <= bmx) res = Math.min(res, acnt+rval);
        }
        System.out.println(res);
    }
}