4 7 18 4 8 57 6 9 16 8 4 5
*
8
+
4
=
4
+
*
15
+
8
=
+
15
*
18
+
=
6
+
18
*
+
=
5
+
7
*
57
+
=
4
+
*
+
13
=
13
+
4
*
+
=
18
+
16
*
42
+
9
=
+