// editor1
#include<stdio.h>
#include<ctype.h>
#include<string.h>
int isAlphabetic(char str[])
{
    for(int i=0;str[i] !='\0';i++)
    {
        if(!isaipha(str[i]))
        {
            return 0;
        }
    }
    return 1;
}
int main()
{
    char s1[105];
    char s2[105];
   fgets(s1,sizeof(s1),stdin);
   fgets(s2,sizeof(s2),stdin);
   s1[strcspn(s1,"\n")]='\0';
   s2[strcspn(s2,"\n")]='\0';
    if(isAlphabetic(s1)&&isAlphabetic(s2))
    {
        printf("%s%s",s1,s2);
    }
    else{
        printf("Invalid input");
    }
    return 0;
}