#!/usr/bin/ruby
# encoding: utf-8

# ABC 123 A - Five Antennas

a = gets.to_i
b = gets.to_i
c = gets.to_i
d = gets.to_i
e = gets.to_i
k = gets.to_i

arr = [a,b,c,d,e]

# これでもOK！
#arr.combination(2).to_a.each {|i,j|
#  if (i-j).abs > k then
#    puts ":("
#    exit
#  end
#}

arr.combination(2) {|i,j|
  if (i-j).abs > k then
    puts ":("
    exit
  end
}

puts "Yay!"
