Working on part 1

part1-intmain.md

@@ -1,3 +1,21 @@
 # Part 1:  `int main`
 
-In C and C++ programs, the 
+The entry point for C and C++ programs is a function called `main`.  The hello world program in C++ looks like this:
+
+```c++
+#include <iostream>
+
+int main(int argc, char** argv)
+{
+    std::cout << "Hello, world." << std::endl;
+
+    return 0;
+}
+```
+
+You can find the `helloworld.cpp` file in this directory.  Compile and run it from the command line like this:
+
+    g++ helloworld.cpp -o helloworld
+    ./helloworld
+    
+