diff --git a/src/Substractor.java b/src/Substractor.java
new file mode 100644
index 0000000..706b576
--- /dev/null
+++ b/src/Substractor.java
@@ -0,0 +1,5 @@
+public class Substractor{
+    public int substract(int x, int y){
+        return x-y;
+    }
+}
\ No newline at end of file
diff --git a/tst/SubstractorTest.java b/tst/SubstractorTest.java
new file mode 100644
index 0000000..848fd28
--- /dev/null
+++ b/tst/SubstractorTest.java
@@ -0,0 +1,7 @@
+public class SubstractorTest {
+   public void testSubstract() {
+     Substractor substractor = new Substractor();
+     int result = substractor.substract(5,2);
+     assert(result==3);
+   }
+}