Need help - avoiding the NULL result of a formula with an unset timeline column

Hello how are you,
I am need help me with a formula to avoid the error that is being generated. I have a board with 5 timeline columns (image attached).
I created a formula to count and add the days of each timeline, but if any of them is not set (that is, if it is NULL), the formula gives an error.

Formula:
MINUS({Total Dias},SUM((DAYS({Cronograma#End},{Cronograma#Start})+1)+(DAYS({Saldo 1#End},{Saldo 1#Start})+1)+(DAYS({Saldo 2#End},{Saldo 2#Start})+1)+(DAYS({Saldo 3#End},{Saldo 3#Start})+1)+(DAYS({Saldo 4#End},{Saldo 4})+1)))