I have 2 errors about syntax that i can't find. it's in if else loop [closed]

I have 2 errors in the if else loop and i don't konow what? Thanks for help me. I am a beginnner.

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

int main(int argc, char* argv[])
{

if (argc != 2)
{ printf("USAGE: cipher <integer key> <encode | decode>\n");
                printf("Then, just type your text and it will automatically output the en/de crypted text! :)\n");

    return 1;
}
int key = atoi(argv[1]);
string s = GetString();

    if (key > 25)
    {
        key = key%26;

            for (int i = 0, longitud = strlen(s); i < longitud; i++)
            {
                int chr = 's[i]';

                if (!isalpha(s[i]))
                {
                    printf("'%c'", chr);
                 else 
                     if (( s[i] >= 'a' && s[i] <= 'z'))
                    {
                        chr =  (chr -'a' + key) % 26 + 'a';
                     printf("'%c'", chr);
                    else 
                        chr = (chr-'A' + key) % 26 + 'A';
                     printf("'%c'", chr);
                    }
                }
             }
        else
            for (int i = 0, longitud = strlen(s); i < longitud; i++)
            {
                int chr = 's[i]';

                if (!isalpha(s[i]))
                {
                    printf("'%c'", chr);

                else
                    if (( s[i] >= 'a' && s[i] <= 'z'))
                    {
                        chr =  (chr -'a' + key) % 26 + 'a';
                     printf("'%c'", chr);

                    else 
                        chr = (chr-'A' + key) % 26 + 'A';
                     printf("'%c'", chr);
                    }
                }
            }
     }

}