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


int main(int argc, string argv[1])
{
    if (argc != 2)
    {
        printf("Usage: ./caesar key\n");

    }

    else
    {



        for (int j = 0, n = strlen(argv[1]); j < n; j++)
        {

            if(isdigit(argv[1][j]))
            {


                printf("%c\n", argv[1][j]);



            }


            else
            {
                printf("Usage: ./caesarkey\n");
                return 1;

            }
        }

    }



}