I ran this Hash in my console << ruby example.rb but my students.count doesn't appear?

gistfile1.rb

#!/bin/ruby

#all those informations are fictive
students = {:VILC22579307 => "VILLENEUVE-ASSE, CINDY",
:NDIJ19129106 => "NDIAYE YEND, JEAN-LOUIS RUDY", 
:JEAJ03108909 => "JEAN-BAPTISTE, JOSEPH-RAYMOND MARC",
:ELME29089109 => "EL MOUTARAJJI EL ALA, ELIAS",
:TRED01039200 => "TREMBLAY, DENIS MARC-ANDRE PIERRE",
:AUCM28579305 => "AUCLAIR-JULIEN, MARIE-ISABELLE"}
students.count
puts "hello world"#only this line appears