Well done! That's the right answer.
Hint



Test
2
+
3
+
3
=
2
+
3
+
4
=
4
+
+
=
3
+
+
=
+
1
+
=
+
4
+
=
+
+
=
+
+
=
+
+
=
+
+
=
0
1
2
3
4
5
6
7
8
9