How to make wide format matrix created in the model section to be long format in the same model section in stan?

Hi all, I have a 5X2 data matrix below created in the model section of stan without any column and row names. Is there a way to make the data to be 10X1 long format? Thanks!

model {

real response[5, 2];
 response <- matrix(c(0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 0.9, 0.8, 0.2, 0.3), ncol = 2)