a = int(input())
b = int(input())
c = int(input())
d = int(input())
e = int(input())
k = int(input())

l = [a, b, c, d, e]
d = list()

for i, x in enumerate(l[:-1]):
    l2 = l[i+1:]
    for y in l2:
        d.append(y-x)

if max(d) <= k:
    print('Yay!')
else:
    print(':(')