Make an example program a bit more interesting

README.md

@@ -39,4 +39,4 @@ As a result, you'll get an `example.raw` binary. To execute it:
 ./rve ../example/example.raw
 ```
 
-The expected output of the example program is `269`.
+The expected output of the example program is `40320`.

example/example.c

@@ -1,9 +1,14 @@
-static int mem = 56;
+static int mem = 1;
+
+int fact(int n) {
+  if (n == 0)
+    return 1;
+
+  return n * fact(n-1);
+}
 
 int main() {
-  int a = 42;
-  int b = 5;
-  mem = mem + a*b + 3;
+  mem = fact(8);
 
   return 0;
 }