Maybe I am missing the point but why not just remove the line
Serial.println(0);
from your program?
By the way, you could remove all the delay(1000) lines in the different IF clauses and replace them with a single delay(1000) as the last item in loop().
Better still, don't use delay() at all as it blocks the Arduino from doing other things during the delay() period. The demo Several Things at a Time illustrates the use of millis() to manage timing without blocking. It may help with understanding the technique.
Have a look at Using millis() for timing. A beginners guide if you need more explanation.
...R