def rangecheck(letter):
        rangel = 65
        rangeh = 90
        if letter < rangel:
            return letter + rangeh - rangel + 1
        elif letter > rangeh:
            return letter - rangeh + rangel - 1
        else:
            return letter

class classic_ceasar:
    def __init__(self,string,shift):
        self.string = string
        self.shift = shift

    def letsgo(self):
        string2 = ''
        for letter in self.string:
            if letter is not " ":
                l_=ord(letter)+self.shift
                string2 += chr(rangecheck(l_))
            else:
                string2 += letter
        return string2

print(classic_ceasar("GCUA VQ DTGCM",-2).letsgo())