#! /usr/bin/env perl6

my %population = (Oslo          => 500_000, 
                  Xyflwizz      => "unknown",
                  Paris         => 5_000_000,
                 "Buenos Aires" => 10_000_000);

my $total = 0;

for %population.values -> $population
{
  $total += $population if $population ~~ Int;
}

say "Total population: $total";