What file type does “PLINK –block” accept as input?

Hi,

I have set of SNPs (distributed over all the chromosomes) and I am trying to do some haplotype block estimation to identify whether some of them are part of the same haplotype block, etc. It seems like “PLINK –blocks” does what I want, but it’s unclear to me what file type to use as input. I have my SNPs as vcf.gz per chromosomes currently. Could someone please help me figure out what file type is appropriate?

Thank you