#include <stdio.h>
#include <cs50.h>
#include <ctype.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>



int main(int argc, string argv[])
{

    //Check the command line for 2 line arguments
    if (argc != 2)
    {
    printf("ERROR: Enter one key on command-line\n");
    return 1;
    }



   // Put argv into an integer (k).
    int k = atoi(argv[1]);
    if (k < 0)
    {
        printf("Enter a positive value\n");
        return 1;
    }

   // Check if (k) is only digits.

    for(int i = 0; i < strlen(argv[1]); i++)
        if(isalpha(argv[1][i]))
        {
            printf("Usage: ./caesar key\n");
            return 1;
        }


}