print("欢迎来到Kaysar解密系统")
kirguz=input("请输入一串字符串:")
surguz = int(input("偏移值"))
for c in kirguz:
      if "a"<=c<="z":
            print(chr(ord("a") + (ord(c) - ord("a") - surguz) %26), end= "")
      elif "A"<=c<="Z":
            print(chr(ord("A") +(ord(c) - ord("A") - surguz) %26), end= "")
      else:
            print(c, end= "")
