def solve(n ,s)
    table = {"A"=> 1,"B"=> 2,"C"=>3,"D"=>4,"E"=>5,
    "F"=>6,"G"=>7,"H"=>8,"I"=>9,"J"=>10,
    "K"=>11,"L"=>12,"M"=>13,"N"=>14,"O"=>15,
    "P"=>16,"Q"=>17,"R"=>18,"S"=>19,"T"=>20,
    "U"=>21,"V"=>22,"W"=>23,"X"=>24,"Y"=>25,
    "Z"=>26}
    mod_n = n % table.length
    # p mod_n
    mapped_l = s.chars.map do |c|
        idx = ((table[c] + n) % table.length) -1
        table.keys[idx]
    end
    mapped_l.join
end

def main()
    n = gets.to_i
    s = gets.chomp
    ans = solve(n ,s)
    p ans
end

main()