import sys

input = sys.stdin.readline


def main():
    h, w, la, lb, ka, kb = map(int, input().split())

    f = lambda x, y: min(h, x * la) * min(w, y * lb) + x * ka + y * kb

    ans = 10**9
    for x in range(h + w + 10):
        low, high = 0, h + w + 10
        if f(x, low) >= h * w:
            ans = min(ans, x)
        else:
            while high - low > 1:
                mid = (high + low) // 2
                if f(x, mid) >= h * w:
                    high = mid
                else:
                    low = mid
            ans = min(ans, x + high)

    print(ans)


if __name__ == "__main__":
    main()