题解 | #高精度整数加法#python3

按位索引即可

while True:
    try:
        str1 = str(input())
        str2 = str(input())

        def str_to_num(str3):
            num1 = 0
            a = len(str3)

            for i in range(a):
                if(str3[i] == '9'):
                    num1 += 9*(10**(a-i-1))
                elif(str3[i] == '8'):
                    num1 += 8*(10**(a-i-1))
                elif(str3[i] == '7'):
                    num1 += 7*(10**(a-i-1))
                elif(str3[i] == '6'):
                    num1 += 6*(10**(a-i-1))
                elif(str3[i] == '5'):
                    num1 += 5*(10**(a-i-1))
                elif(str3[i] == '4'):
                    num1 += 4*(10**(a-i-1))
                elif(str3[i] == '3'):
                    num1 += 3*(10**(a-i-1))
                elif(str3[i] == '2'):
                    num1 += 2*(10**(a-i-1))
                elif(str3[i] == '1'):
                    num1 += 1*(10**(a-i-1))
                elif(str3[i] == '0'):
                    num1 = num1
            return num1

        num2 = str_to_num(str1)
        num3 = str_to_num(str2)

        print(num2+num3)
    except:
        break