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

ok = 0
ng = 100000000000

while ng-ok > 1:
	mid = (ok+ng)//2
	a,b,c,d = A,B,C,D
	cost = mid*P
	
	insufficient = 0
	insufficient += max(0, mid-a) + max(0, mid-b) + max(0, mid-c)
	
	over = 0
	over += max(0, a-mid) + max(0, b-mid) + max(0, c-mid) + d
	
	if insufficient > over:
		ng = mid
		continue
	
	cost += insufficient*Q
	
	if cost <= R:
		ok = mid
	else:
		ng = mid
print(ok)