import sys

class alphabet: #Trueなら大文字
    def __init__(self, capitalize):
        self.num = dict() #アルファベットを数字に変換
        self.abc = ["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"]
        if capitalize: 
            for i in range(26): self.abc[i] = self.abc[i].upper()
        for i, a in enumerate(self.abc): self.num[a] = i


def solve():
    input = sys.stdin.readline
    N = int(input())
    S = input().strip("\n")
    Ans = ""
    Alphabet = alphabet(True)
    for i in range(len(S)):
        sNum = Alphabet.num[S[i]]
        rotateNum = (sNum + N) % 26
        Ans += Alphabet.abc[rotateNum]
    print(Ans)

    return 0

if __name__ == "__main__":
    solve()
f091d5dd1a64530d70ff1a648c785ec67b8ce904
<mask token>


class alphabet:
    <mask token>


<mask token>

<mask token>


class alphabet:

    def __init__(self, capitalize):
        self.num = dict()
        self.abc = ['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']
        if capitalize:
            for i in range(26):
                self.abc[i] = self.abc[i].upper()
        for i, a in enumerate(self.abc):
            self.num[a] = i


def solve():
    input = sys.stdin.readline
    N = int(input())
    S = input().strip('\n')
    Ans = ''
    Alphabet = alphabet(True)
    for i in range(len(S)):
        sNum = Alphabet.num[S[i]]
        rotateNum = (sNum + N) % 26
        Ans += Alphabet.abc[rotateNum]
    print(Ans)
    return 0


<mask token>

<mask token>


class alphabet:

    def __init__(self, capitalize):
        self.num = dict()
        self.abc = ['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']
        if capitalize:
            for i in range(26):
                self.abc[i] = self.abc[i].upper()
        for i, a in enumerate(self.abc):
            self.num[a] = i


def solve():
    input = sys.stdin.readline
    N = int(input())
    S = input().strip('\n')
    Ans = ''
    Alphabet = alphabet(True)
    for i in range(len(S)):
        sNum = Alphabet.num[S[i]]
        rotateNum = (sNum + N) % 26
        Ans += Alphabet.abc[rotateNum]
    print(Ans)
    return 0


if __name__ == '__main__':
    solve()

import sys


class alphabet:

    def __init__(self, capitalize):
        self.num = dict()
        self.abc = ['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']
        if capitalize:
            for i in range(26):
                self.abc[i] = self.abc[i].upper()
        for i, a in enumerate(self.abc):
            self.num[a] = i


def solve():
    input = sys.stdin.readline
    N = int(input())
    S = input().strip('\n')
    Ans = ''
    Alphabet = alphabet(True)
    for i in range(len(S)):
        sNum = Alphabet.num[S[i]]
        rotateNum = (sNum + N) % 26
        Ans += Alphabet.abc[rotateNum]
    print(Ans)
    return 0


if __name__ == '__main__':
    solve()

import sys

class alphabet: #Trueなら大文字
    def __init__(self, capitalize):
        self.num = dict() #アルファベットを数字に変換
        self.abc = ["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"]
        if capitalize: 
            for i in range(26): self.abc[i] = self.abc[i].upper()
        for i, a in enumerate(self.abc): self.num[a] = i


def solve():
    input = sys.stdin.readline
    N = int(input())
    S = input().strip("\n")
    Ans = ""
    Alphabet = alphabet(True)
    for i in range(len(S)):
        sNum = Alphabet.num[S[i]]
        rotateNum = (sNum + N) % 26
        Ans += Alphabet.abc[rotateNum]
    print(Ans)

    return 0

if __name__ == "__main__":
    solve()