a=[]
for i in 0..4
  a[i]=gets.chomp.to_i
end
k=gets.chomp.to_i

t=true
for i in 0..4
  for j in 0..4
    if (a[i]-a[j]).abs > k
      puts ":("
      t=false
      break
    end
  end
  break unless t
end

if t
  puts "Yay!"
end