alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split("")

N = gets.chomp.to_i
word = gets.chomp.split("")

word.each_with_index do |e,i|
  ind = alpha.index(e)
  if ind + N < 26
	  word[i] = alpha[ind + N]
  else
    word[i] = alpha[ind + N - 26]
  end
end

puts word.join("")