#include<stdio.h>
#include<ctype.h>
void main()
{
    char s1[100],s2[100];
    scanf("%s",&s1);
    scanf("\n%s",&s2);
    if(isalpha(s1)&&isalpha(s2))
    {
        printf("\n%s%s",s1,s2);
    }
    else
    {
        printf("\nInvalid input");
    }
    
}