diff --git a/CM2005 Object Oriented Programming/Topic 1/1.7.1/a.exe b/CM2005 Object Oriented Programming/Topic 1/1.7.1/a.exe
new file mode 100644
index 0000000..712e017
Binary files /dev/null and b/CM2005 Object Oriented Programming/Topic 1/1.7.1/a.exe differ
diff --git a/CM2005 Object Oriented Programming/Topic 1/1.7.1/main.cpp b/CM2005 Object Oriented Programming/Topic 1/1.7.1/main.cpp
new file mode 100644
index 0000000..ecdd45d
--- /dev/null
+++ b/CM2005 Object Oriented Programming/Topic 1/1.7.1/main.cpp	
@@ -0,0 +1,26 @@
+#include <iostream>
+
+int difference(int a, int b);
+
+void printHello()
+{
+  std::cout << "Hello" << std::endl;
+}
+
+/** compute the average of x and y**/
+float average(float x, float y)
+{
+  float sum;
+  sum = x+y;
+  return (x+y)/2;
+}
+
+int main()
+{
+  printHello();
+  float a = average(15, 23);
+  std::cout << a << std::endl;
+  int c = difference(10, 7);
+  std::cout << c << std::endl;
+  return 0;
+}
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diff --git a/CM2005 Object Oriented Programming/Topic 1/1.7.1/side.cpp b/CM2005 Object Oriented Programming/Topic 1/1.7.1/side.cpp
new file mode 100644
index 0000000..7e7008e
--- /dev/null
+++ b/CM2005 Object Oriented Programming/Topic 1/1.7.1/side.cpp	
@@ -0,0 +1,6 @@
+#include <iostream>
+
+int difference(int a, int b)
+{
+  return a-b;
+}
\ No newline at end of file