//Get spell and journal name
    string spellName = spell->revealScrollName();
    string journal = SpellJournal::journal;  

    // Initialize the memoization table with -1 (indicating uncomputed)
    int n = spellName.size();
    int m = journal.size();
    //memo is used to keep track of the computation, avoiding usless computation
    vector<vector<int>> memo(n + 1, vector<int>(m + 1, -1)); 

    auto f = [&spellName, &journal, &memo](int n, int m, auto& f) -> int {
        if (n == 0 || m == 0) return 0; //Reached the end of one string
        if (memo[n][m] != -1) return memo[n][m]; //If already computed
        
        if (spellName[n - 1] == journal[m - 1]) { //Update memo adding the new computation
            memo[n][m] = 1 + f(n - 1, m - 1, f);
        } else {
            memo[n][m] = std::max(f(n - 1, m, f), f(n, m - 1, f)); //Recall f over n-1 and m-1 to gety the substring which return the  highest value
        }
        return memo[n][m]; // Return the computed result
    };