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

def judge(k):
    remain = R - P*k
    short = max(0, k - A) + max(0, k - B) + max(0, k - C)
    amari = D + max(0, A-k) + max(0, B-k) + max(0, C-k)
    # print(k, remain, short, amari, short*Q)
    if short > amari: return False
    return short*Q <= remain

ok = 0
ng = R//P + 1
while abs(ok-ng) > 1:
    mid = (ok+ng) // 2
    if judge(mid): ok = mid
    else: ng = mid

print(ok)