import sys

# Defining constants
pi = 3.141592653589793
inf = 2 * 1e9
linf = 4 * 1e18
mod1 = 1000000007
mod2 = 998244353

# Functions to find maximum or minimum
def chmax(a, b):
    if a < b:
        return b, True
    return a, False

def chmin(a, b):
    if a > b:
        return b, True
    return a, False

def main():
    # Reading input
    H, W, La, Lb, Ka, Kb = map(int, sys.stdin.readline().split())

    ans = linf
    for i in range(1000001):
        if i == 0:
            if Kb > 0:
                ans = (H * W - 1) // Kb + 1
            continue

        ok = 10**12 + 1
        ng = -1
        while ok - ng > 1:
            mid = (ok + ng) // 2
            if min(H, i * La) * min(W, Lb * mid) + i * Ka + mid * Kb >= H * W:
                ok = mid
            else:
                ng = mid

        ans, _ = chmin(ans, i + ok)
    
    print(int(ans))

if __name__ == "__main__":
    main()