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

if b - a > k then
  puts ":("
elsif c - a > k then
  puts ":("
elsif d - a > k then
  puts ":("
elsif e - a > k then
  puts ":("
elsif c - b > k then
  puts ":("
elsif d - b > k then
  puts ":("
elsif e - b > k then
  puts ":("
elsif d - c > k then
  puts ":("
elsif e - c > k then
  puts ":("
elsif e - d > k then
  puts ":("
else
  puts "Yay!"
end
