A = gets.split.map(&:to_i)
B = gets.split.map(&:to_i)
C = gets.split.map(&:to_i)
D = gets.split.map(&:to_i)
E = gets.split.map(&:to_i)
K = gets.split.map(&:to_i)

def CulcDistance(x,y)
  num = x-y
  rs = num.abs
  if num < k
    return result = "true"
  else
    return result = "false"
  end
end

CulcDistance(A,B)
CulcDistance(A,C)
CulcDistance(A,D)
CulcDistance(A,B)
CulcDistance(A,E)
CulcDistance(B,C)
CulcDistance(B,D)
CulcDistance(B,E)
CulcDistance(C,D)
CulcDistance(C,E)
CulcDistance(D,E)

if result == "true"
  puts "Yay!"
else
  puts ":("
end
