#include <iostream>
using namespace std;

class BigNumber
{
    private:
        string number = "";
    public:
    void concatinateNumber(string a)
    {
        number = number + a;

    }

     long long int getNumber()
    {
         return stoll(number);

    }

};

int main() {
	BigNumber bigNum;

	bigNum.concatinateNumber("1");
	bigNum.concatinateNumber("2");

	cout<<bigNum.getNumber();

	return 0;
}