#!/usr/bin/perl
#
# Problem 1: 
# If we list all the natural numbers below 10 that are multiples of 3 or 5, 
# we get 3, 5, 6 and 9. The sum of these multiples is 23.
# Find the sum of all the multiples of 3 or 5 below 1000.
#

$ans = 0;

for ($c = 3; $c < 1000; $c++) {
  if(($c % 5) == 0 || ($c % 3) == 0){
  $ans+=$c;
  }
}

print $ans;