Well done! That's the right answer.
Hint



3
+
1
=
2
+
2
=
1
+
3
=
2
+
3
=
3
+
2
=
4
+
1
=
3
+
3
=
1
+
5
=
2
+
4
=
5
+
1
=
0
1
2
3
4
5
6