#include<stdio.h>
#include<ctype.h>
#include<string.h>
int isAlphaOnly(char str[])
{
    for(int i=0;str[i] !='\0';i++)
    {
        if(!isalpha((unsigned char)str[i]))
        {
            return 0;
        }
    }
    return 1;
}
int main()
{
    char s1[101],s2[101];
    if(scanf("%100s",s1) !=1)return 0;
    if(scanf("%100s",s2) !=1)return 0;
    if(isAlphaOnly(s1)&&isAlphaOnly(s2))
    {
        printf("%s %s\n",s1,s2);
    }
    else
    {
        printf{"Invalid input\n");
    }
        return 0;
}