Well done! That's the right answer.
Hint



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