N = gets.to_i
S = gets.chomp

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']

result = ''
for c in S.chars
  x = alf.index(c)
  x = ( x + N ) % 26
  result += alf[x]
end

puts result