Code Idea Task 2

#include <iostream>
#include <cstring>
using namespace std;

int main() {
    char str[20];
    char str2[20];

    int idx1 = 0; // index for str array
    int idx2 = 0; // index for str2 array

    // read the input
    cin.getline(str, 20); // <--- Vuvedi mu "I am a string"

    int str_len = strlen(str);

    int M = 4;
    int L = 3;

    idx2 = 3; // Tova trqbva da si go izchislish tochno kolko trqbva da e
    for (int i = 0; i < str_len; i++) {
        if (idx2 == str_len) {
            idx2 = 0;
        }

        str2[idx2] = str[i];
        idx2++;
    }

    for (int i = 0; i < str_len; i++) {
        cout << (char) (str2[i] + M);
    }

    return 0;
}