Linux Mint och Eclipse: Fel: Hittar inte main metoden

package f3;

public class Addition {
	// -----------------------------------------------------------------
	// Concatenates and adds two numbers and prints the results.
	// -----------------------------------------------------------------
	public static void main(String[] args) {
		System.out.println("24 and 45 concatenated: " + 24 + 45);

		System.out.println("24 and 45 added: " + (24 + 45));
	}
}

 package f3;

public class StartWelcome1 {
    public static void main(String[] args) {
        Welcome1 prog = new Welcome1();
        prog.todo();
    }
}