Hi everyone. I've received impute2 files in gz format and I want to running in SNPTEST

I use the next command

./snptest -data /Users/claudiacolmenares/Desktop/PA_gwas_chr_4_python_filtered.impute2.gz.gen /Users/claudiacolmenares/Desktop/PA_gwas_chr_4_python_filtered.impute2.gz.sample  -summary_stats_only -o /example/ex.out

And this is the error message

Welcome to SNPTEST v2.5.2 (revision 675f81d8832d51b2d556fd962912b2ca96cfa6c6)
© University of Oxford 2008-2015
https://mathgen.stats.ox.ac.uk/genetics_software/snptest/snptest.html
Read LICENCE file for conditions of use.

==============

Data Files : 
 -gen files : /Users/claudiacolmenares/Desktop/PA_gwas_chr_4_python_filtered.impute2.gz.gen 
 -sample files : /Users/claudiacolmenares/Desktop/PA_gwas_chr_4_python_filtered.impute2.gz.sample 

Tests : 
 (no tests specified)
 -method none

reading sample exclusion lists

Inspecting data (this may take some time)...
!! Error detected in source "/Users/claudiacolmenares/Desktop/PA_gwas_chr_4_python_filtered.impute2.gz.sample".
!! Quitting.
libc++abi.dylib: terminating with uncaught exception of type genfile::ResourceNotOpenedError: genfile::ResourceNotOpenedError
Abort trap: 6

I also tried this command

./snptest -data /Users/claudiacolmenares/Desktop/PA_gwas_chr_4_python_filtered.impute2.gz.gen -summary_stats_only -o /example/ex.out

But I have this error message

ERROR: -data must be supplied an even number of values.

Any suggestions to solve this??? Thanks!!