#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("Usage: ./caesarkey\n");

               return 1;

            }


       }
            int k = atoi(argv[1]);
            printf( "Success\n");
            printf("%i\n", k);