r, p, q = map(int, input().split())
a, b, c, d = map(int, input().split())

ok = 0
ng = 10**9+1
while ng - ok > 1:
    mid = (ng + ok) // 2
    
    if (a + b + c + d) // 3 < mid:
        ng = mid
    else:
        cost = max(0, q * (mid - a)) + max(0, q * (mid - b)) + max(0, q * (mid - c))
        cost += p * mid
        if cost > r:
            ng = mid
        else:
            ok = mid

print(ok)