enter = []
upenter = []
ans = "Yay!"
for i in 0..5 do
    enter[i] = gets.chomp.to_i 
    if i == 1
        upenter[0] = enter[i] - enter[i-1]
         
    elsif i == 2
        upenter[1] = enter[i] - enter[i-1]
        upenter[2] = enter[i] - enter[i-2]
    elsif i == 3
        upenter[3] = enter[i] - enter[i-1]
        upenter[4] = enter[i] - enter[i-2]
        upenter[5] = enter[i] - enter[i-3]
    elsif i == 4
        upenter[6] = enter[i] - enter[i-1]
        upenter[7] = enter[i] - enter[i-2]
        upenter[8] = enter[i] - enter[i-3]
        upenter[9] = enter[i] - enter[i-4]
    end
end
upenter.select do |x|
    if x > enter[5]
        ans = ":("
        break
    end
end
puts ans