N = gets.chomp.to_i
S = gets.chomp.split('')
ans = []

alf = ['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']
S.each do |s|
  i = alf.find_index(s) + N
  ans << alf[i % 26]
end
puts ans.join('')