@Override
        public void run() {
            for (int index = start; index < finish; index++) {
                if (index >= size * size) {
                    return;
                }
                int i = index / size;
                int j = index - size * i;
                int matrixElement = 0;
                for (int k = 0; k < size; k++) {
                    matrixElement += first[i][k] * second[k][j];
                }
                result[i][j] = matrixElement;
            }
        }