#include<stdio.h>
int main()
{
    int n,m,num;
    scanf("%d\n",n);
    scanf("%d\n",m);
    scanf("%d\n",num);
    if(num!=0||num!=1);
    {
        printf("Invalid input");
    }
    else
    {
        printf("%d",n);
        printf("%d",m);
    }
    return 0;
}