#include <iostream>
#include <string>


using namespace std;

int main()
{
    string s1, s2, s3;
    bool mazani_s1 = true;
    bool mazani_s2 = true;
    bool mazani_s3 = true;
    bool add = false;

    cout << "Zadejte dve binarni cisla:" << endl;
    cin >> s1;
    cin >> s2;

    //osetreni vstupu proti jinym znakum, nez 1 nebo 0 a smazani prebytecnych nul na zacatku

    for (unsigned int i = 0; i < s1.length(); i++)
    {
        if ((s1[i] != '0') && (s1[i] != '1'))
        {
            cout << "Nespravny vstup." << endl;
            return 0;
        }

        if (s1[i] == 49)
        {
            mazani_s1 = false;
        }

        if (s1[i] == 48 && mazani_s1 == true)
        {
            s1.erase(i, 1);
            i = -1;
        }

    }

    for (unsigned int i = 0; i < s2.length(); i++)
    {
        if ((s2[i] != '0') && (s2[i] != '1'))
        {
            cout << "Nespravny vstup." << endl;
            return 0;
        }

        if (s2[i] == 49)
        {
            mazani_s2 = false;
        }

        if (s2[i] == 48 && mazani_s2 == true)
        {
            s2.erase(i, 1);
            i = -1;
        }
    }

    while (s1.length() != s2.length())
    {
        if (s1.length() > s2.length())
        {
            s2 = "0" + s2;
        }
        else s1 = "0" + s1;
    };

    s2 = "0" + s2;
    s1 = "0" + s1;

    unsigned int i = s1.length();

    do
        {
            if (s1[i] == '1' && s2[i] == '1')
            {
                if (add == true)
                {
                    s3 = "1" + s3;
                }
                else
                {
                    s3 = "0" + s3;
                    add = true;
                }
            }

            if (s1[i] == '0' && s2[i] == '0')
            {
                if(add == true)
                {
                    s3 = "1" + s3;
                    add = false;
                }
                else
                {
                    s3 = "0" + s3;
                    add = false;
                }

            }

            if (s1[i] == '1' && s2[i] == '0')
            {

                if (add == true)
                {
                    s3 = "0" + s3;
                }
                else
                {
                    s3 = "1" + s3;
                    add = false;
                }
            }


            if (s1[i] == '0' && s2[i] == '1')
            {
                if (add == true)
                {
                    s3 = "0" + s3;
                }
                else
                {
                    s3 = "1" + s3;
                    add = false;
                }
            }
    --i;
    } while (i != 0);


    if (add == true)
    {
        s3 = "1" + s3;
    }

    for (unsigned int i = 0; i < s3.length(); i++)
    {

        if (s3[i] == 49)
        {
            mazani_s3 = false;
        }

        if (s3[i] == 48 && mazani_s3 == true)
        {
            s3.erase(i, 1);
            i = -1;
        }
    }


    cout << "Soucet: " << s3 << endl;


    return 0;

}