> #include <iostream>
> 
> using namespace std;
> 
> int main()
> {
>     char a[1000000], b[1000000], j;
>     long N, i;
>     cin >> N;
>     getchar();
>     for (i = 0; i < N; i++)
>     {
>         a[i] = getchar();
>         getchar();
>         b[i] = getchar();
>         getchar();
>     }
>     j = 0;
>     for (i = N - 1; i >= 0; i--)
>     {
>         a[i] += b[i] + j - 48;
>         j = 0;
>         if (a[i] > 57)
>         {
>             a[i] -= 10;
>             j = 1;
>         }
>     }
>     for (i = 0; i < N; i++)
>         putchar(a[i]);
>     cout << endl;
>     return 0;
> }