#include<stdio.h>
#include<ctype.h>
#include<string.h>
int main()
{
    char s1[100],s2[50];
    scanf("%s%s",&s2[100],&s2[]);
    if(isalpha(s1) && isalpha(s2))
    {
        printf("%s",strcat(s1,s2));
        return 0;
    }
    else
    {
        printf("Invalid input");
    }
}