public int indexOf(Mystring m) {
        for (int i = 0; i < this.pituus; i++) {
            if (this.mjono[i] == m.charAt(0)) {
                int c = 0;
                for (int j = i; j < this.pituus; j++) {
                    if (this.mjono[j] != m.charAt(c))
                        break;
                    if (m.length() == (c + 1))
                        return i;
                    c++;
                }
            }
        }
        return -1;

    }