I have a list of 300 $p$ values selected from all $p$ values obtained in multiple testing such that $p<.05$. I do not know the values of $p>.05$ or their number. The $p$ values are not corrected for multiple testing, and I would like to do so for the 300 raw $p$ values that I have.
Is it OK to apply the Benjamini-Hochberg correction method, for instance with
p.adjust() in R, on my list of $p$ values even though they have been pre-selected for being less than $.05$? If not, is there another method that can be used?