a= int(input()) s=' ' b=[] for i in input(): i=ord(s.join(i)) b.append(i) #print(b) for i in (b): if i<=90: i=i-(a%26) if i<65: i=i+26 if i>90: i=i-(a%26) if i<97: i=i+26 print(chr(i),end="")
