/* Nedorezov Egor 108 group
24 var */

#include <iostream>
#include <stdlib.h>
#include <math.h>

using namespace std;

int main()
{
        char a[1], b[1];

        cout<<"enter a"<<endl<<flush;
        for (int i = 0; i < 2; i++)
                cin>>a[i];

        cout<<"enter b"<<endl<<flush;
        for (int j = 0; j < 2; j++)
                cin>>b[j];

        int a1[1], b1[1];
        char check[] = "0123456789ABCDEF";

        for (int numa = 0; numa <= 1; numa++)
        {
            for (int k = 0; k <= 15; k++)
                if (a[numa] == check[k]) a1[numa] = k;
        }

        for (int numb = 0; numb <= 1; numb++)
        {
            for (int l = 0; l <= 15; l++)
                if (a[numb] == check[l]) b1[numb] = l;
        }

        int a10 = a1[0] * 16 + a1[1];
        int b10 = b1[0] * 16 + b1[1];

        int res10 = a10 + b10; int cnt;

        if ( ((res10 / 16) / 16) == 0 ) cnt = 1; else cnt = 2;

        char res16[2], ans[2];

        res16[0] = res10 % 16;
        res16[1] = (res10 / 16) % 16;
        res16[2] = (res10 / 16) / 16;

        for ( int m = 0; m <= 2; m++)
        {
            for (int n = 0; n <= 15; n++)
                if (res16[m] == check[n]) ans[m] = check[n];
        }
    for (int o = 0; o <= cnt; o++)
        cin>>ans[o];
}