Add an argument to enable yield

cm/Main.java

@@ -3,6 +3,16 @@ public class Main {
 		Thread tA, tB;
 		boolean doYield = false;
 
+		if (argv.length == 1) {
+			if (argv[0].equals("true"))
+				doYield = true;
+		}
+		else {
+			System.err.println("Wrong number of arguments.");
+			System.out.println("Usage : java Main true|false");
+			return;
+		}
+
 		if (doYield)
 			System.out.println("Do yield");
 		else