#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <ctype.h>

bool all_alpha(const char *str)
{
    char c;

    while ((c = *str++) != '\0')
        if (!isalpha(c))
            return false;
    return true;
}

int main (int argc, char *argv[])
{
    char *prenom = argv[1];
    char *nom = argv[2];

    if(!all_alpha(prenom))
        printf("\"%s\" is not a valid firstname\n", prenom);
    else if(!all_alpha(nom))
        printf("\"%s\" is not a valid lastname\n", nom);
    else
    {
        char nomU[9] = {0};
        int i;
        for(i = 0; i < strlen(nom) && i < 7; i++)
            if(nom[i] >= 'A' && nom[i] <= 'Z')
                nomU[i] = (char)(nom[i] - 'A' + 'a');
            else
                nomU[i] = nom[i];

        if(prenom[0] >= 'A' && prenom[0] <= 'Z')
            nomU[i] = (char)(prenom[0] - 'A' + 'a');
        else
            nomU[i] = prenom[0];

        printf("%s\n", nomU);
    }


	return 0;
}