/**
 * pset 2
 * Caesar's Cipher
 *
 * Mike
 *
 * Scrambles a message by k characters
 */

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

int main(int argc, string argv[])
{
if(argc != 2 || atoi(argv[1]) < 1)
{
printf("error\n");
return 1;
}

// get k

    int k = atoi(argv[1]);
    int i;


// get message

    string scramble = GetString();

// scramble and output

    for(i = 0; i < strlen(scramble); i++)
    {
        //lowercase
        if(isupper(scramble[i]))
        {
            int code = (scramble[i] - 65 + k) %26;
            printf("%c", (char) code + 65);
        }
        //uppercase
        else if(islower(scramble[i]))
        {
            int code = (scramble[i] - 97 + k) %26;
            printf("%c", (char) code + 97);
        }
        else (printf("%c", scramble[i]));
    }
    printf("\n");
    return 0;
}