h, w, la, lb, ka, kb = map(int, input().split())
ans = 1 << 30

for a in range(h + w + 1):
    l = 0
    r = ans - a

    while r - l > 1:
        b = (l + r) // 2
        c = min(a * la, h) * min(b * lb, w)
        c += a * ka + b * kb
        if c >= h * w:
            r = b
        else:
            l = b
    ans = min(ans, a + r)

for b in range(h + w + 1):
    l = 0
    r = ans - b

    while r - l > 1:
        a = (l + r) // 2
        c = min(a * la, h) * min(b * lb, w)
        c += a * ka + b * kb
        if c >= h * w:
            r = a
        else:
            l = a
    ans = min(ans, b + r)

print(ans)