i got one small question. i want a timer to start and count in my program after a start it. i got an opening screen and if i press enter it goes to the main screen and i want the timer to start then instead of the beginning of the program. i made an small example of what is in my code. maybe you guys can help me.

here is my code:

2. int begintime = 5;
3. int window = 0;
4. 
   
5. void setup() {
6.   size(400, 400);
7.   background(0);
8. }
9. 
   
10. void draw() {
11.   if (window == 0) {
12.     background(#FF0000);
13.   }
14.   if(window == 1) {
15.     background(#FFFFFF);
16.     int sec = frameCount/60;
17.     int timer = begintime - sec;
18. 
    
19.     if (timer <= 0) {
20.       window = 2;
21.     }
22.   }
23. 
    
24.   if(window == 2){
25.    background(0);
26.   }
27. }
28. 
    
29.   void keyPressed() {
30.     if (keyCode == ENTER) {
31.       window =1;
32.     }
33.   }

Thanks in advance