How to interpret de result of a ADFTEST?

Hi, im trying to do a ADFTEST in matlab, but i don´t understand my results. Im doing the adftest with this command structure: [h1,pValue1,stat1,cValue1,reg1] = adftest(Datos,'alpha',0.1,'model','TS','lags',0:20);

I have many questions about this structure, for example: ¿how many lag select? ¿which model select?, i choose 'TS', because i'm trying for test if my time serie its stationary.

Finally, i did the test to three confidence intervals: alpha= 0.1 (90%) alpha= 0.05 (95%) alpha= 0.01 (99%)

from lag 0 to lag 20, and i have a result very confuse, because "stat < critical value" for some lags, but for other lags "stat > critical value", ¿how can interpter this ambiguous results?

Stat

-3,4741 -3,2300 -3,0697 -2,6404 -2,3637 -2,3493 -2,3249 -2,7906 -2,8176 -2,7023 -2,7414 -2,5128 -2,3363 -2,5324 -2,6678 -2,4744 -2,4162 -2,4782 -2,5822 -2,3520 -2,2694

cValue

-2,5740 -2,5741 -2,5741 -2,5741 -2,5742 -2,5742 -2,5742 -2,5742 -2,5743 -2,5743 -2,5743 -2,5744 -2,5744 -2,5744 -2,5745 -2,5745 -2,5745 -2,5745 -2,5746 -2,5746 -2,5746

I hope that someone can helpme.

thanks