R, P, Q = map(int, input().split())
A, B, C, D = map(int, input().split())
total = A + B + C + D

def check(num):
    if total < 3 * num:
        return False
    res = P * num
    lack = 0
    lack += max(num - A, 0)
    lack += max(num - B, 0)
    lack += max(num - C, 0)
    res += lack * Q
    if res <= R:
        return True
    else:
        return False

ok = 0
ng = 10**10
while ok + 1 < ng:
    mid = (ok + ng) // 2
    if check(mid):
        ok = mid
    else:
        ng = mid
print(ok)