bets = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

n = gets.chomp.to_i
text_b = gets.chomp.split("")
text_a = ""

text_b.each do |t|
  tmp_n = bets.index(t) + n
  if tmp_n >= 26 then
    tmp_n -= 26
  end
  tmp_s = bets[tmp_n]
  text_a += tmp_s
end

puts text_a
