def solve(n ,s)
    table = {"A"=> 0,"B"=> 1,"C"=>2,"D"=>3,"E"=>4,
    "F"=>5,"G"=>6,"H"=>7,"I"=>8,"J"=>9,
    "K"=>10,"L"=>11,"M"=>12,"N"=>13,"O"=>14,
    "P"=>15,"Q"=>16,"R"=>17,"S"=>18,"T"=>19,
    "U"=>20,"V"=>21,"W"=>22,"X"=>23,"Y"=>24,
    "Z"=>25}
    mapped_l = s.chars.map do |c|
        idx = (table[c] + n) % table.length
        table.keys[idx]
    end
    mapped_l.join
end

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

main()