using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Test()
    {
        var r = new Random();
        var count = 0;
        var max = 2000;
        while (true)
        {
            var h = r.Next(max) + 1;
            var w = r.Next(max) + 1;
            var la = r.Next(max) + 1;
            var lb = r.Next(max) + 1;
            var ka = r.Next(max);
            var kb = r.Next(max);
            // 愚直解
            var s1 = All(h, w, la, lb, ka, kb);
            // 作成解
            var s2 = Attack(h, w, la, lb, ka, kb);
            if (s1 != s2)
            {
                WriteLine($"{h} {w} {la} {lb} {ka} {kb}");
                WriteLine(s1);
                WriteLine(s2);
                return;
            }
            ++count;
            if (count % 10 == 0) WriteLine(count);
        }
    }
    static long All(long h, long w, long la, long lb, long ka, long kb)
    {
        var ans = long.MaxValue;
        for (var ai = 0; Math.Max(ai, ai * ka) <= h * w + ka; ++ai) for (var bi = 0; Math.Max(bi, bi * kb) <= h * w + kb; ++bi)
        {
            var hs = Math.Min(h, ai * la);
            var ws = Math.Min(w, bi * lb);
            if (hs * ws + ai * ka + bi * kb >= h * w) ans = Math.Min(ans, ai + bi);
        }
        return ans;
    }
    static void Solve()
    {
        var c = NList;
        var (h, w, la, lb, ka, kb) = (c[0], c[1], c[2], c[3], c[4], c[5]);
        WriteLine(Attack(h, w, la, lb, ka, kb));
    }
    static long Attack(long h, long w, long la, long lb, long ka, long kb)
    {
        var horimax = (h + la - 1) / la;
        var vertmax = (w + lb - 1) / lb;
        var ans = horimax + vertmax;
        var kmax = Math.Max(ka, kb);
        if (kmax == 0)
        {
            return ans;
        }
        if (ka > 0) ans = Math.Min(ans, (h * w + ka - 1) / ka);
        if (kb > 0) ans = Math.Min(ans, (h * w + kb - 1) / kb);
        for (var ai = 0; ai <= h; ++ai)
        {
            if (ai == 0 && kb == 0) continue;
            var ok = h * w;
            var ng = -1L;
            while (ok - ng > 1)
            {
                var mid = (ok + ng) / 2;
                var hs = Math.Min(h, ai * la);
                var ws = Math.Min(w, mid * lb);
                var cnt = hs * ws + ai * ka + mid * kb;
                if (cnt >= h * w) ok = mid;
                else ng = mid;
            }
            ans = Math.Min(ans, ai + ok);
        }
        for (var bi = 0; bi <= w; ++bi)
        {
            if (bi == 0 && ka == 0) continue;
            var ok = h * w;
            var ng = -1L;
            while (ok - ng > 1)
            {
                var mid = (ok + ng) / 2;
                var hs = Math.Min(h, mid * la);
                var ws = Math.Min(w, bi * lb);
                var cnt = hs * ws + bi * kb + mid * ka;
                if (cnt >= h * w) ok = mid;
                else ng = mid;
            }
            ans = Math.Min(ans, bi + ok);
        }
        return ans;
    }
}