int go(int i, int numW, int numBlue, int numR, int numBlack, int currWeight) {
    if (i == N)
        // checkMin check that we have the minumum number of each colored item
        return (checkMin(numW, numBlue, numR, numBlack) && numW + numBlue + numR + numBlack == 12) ? 0 : -10000; 
    int res = -10000;
    res = max(res, go(i + 1, numW, numBlue, numR, numBlack, currWeight));
    //canAddItem check if we can add current item without exceeding the max Weight and not excedding the max number of each colored item
    if (canAddItem(items[i], numW, numBlue, numR, numBlack, currWeight)) {  
        if (items[i].color.equals("W")) numW++;
        if (items[i].color.equals("Blue")) numBlue++;
        if (items[i].color.equals("R")) numR++;
        if (items[i].color.equals("Black")) numBlack++;
        res = max(res, items[i].value + go(i + 1, numW, numBlue, numR, numBlack, (items[i].weight + currWeight)));
    }
    return res;
}

boolean checkMax(int numW, int numBlue, int numR, int numBlack) {
    return numW <= 1 && numBlue <= 5 && numR <= 5 && numBlack <= 3;
}

boolean checkMin(int numW, int numBlue, int numR, int numBlack) {
    return numW == 1 && numBlue >= 3 && numR >= 3 && numBlack >= 1;
}

boolean canAddItem(Item item, int numW, int numBlue, int numR, int numBlack, int currWeight) {
    if (item.color.equals("W")) numW++;
    if (item.color.equals("Blue")) numBlue++;
    if (item.color.equals("R")) numR++;
    if (item.color.equals("Black")) numBlack++;
    currWeight += item.cost;
    return checkMax(numW, numBlue, numR, numBlack) && currWeight <= W && numW + numDef + numMid + numAtt <= 12;
}