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

def check(n):
    cost = P * n
    free = sum([max(A-n,0), max(B-n,0), max(C-n,0), D])
    need = sum([max(n-A,0), max(n-B,0), max(n-C,0)])
    if(free < need):return False
    cost += need * Q
    return cost <= R

ok,ng = 0,10**18
while(ng - ok > 1):
    mid = (ok+ng)//2
    if(check(mid)):
        ok = mid
    else:
        ng = mid
print(ok)