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

l = 0
r = min(R/P, (A+B+C+D) // 3) + 1
    
while (r - l) > 1:
    cen = (l+r) // 2
        
    cnt = max(0, cen - A) + max(0, cen - B) + max(0, cen - C)
    cnt = cnt * Q
        
    cnt = cnt + cen * P
        
    if cnt > R:
        r = cen
    else :
        l = cen

print(int(l))