chap2.4

#include <cs50.h>
#include <stdio.h>

int main(int argc, string argv[])
{
    if (argc != 3)
    {
        printf("Usage: ./exit <firstname> <lastname>\n");
        return 1;
    }
    
    // prints out hello followed by firstname, lastname  
    printf("Hello, %s %s!\n", argv[1], argv[2]);
    return 0;
        
}