#!/usr/bin/perl -Tw

use strict;
use warnings;

use Date::Day;

my $sum = 0;
for (my $y = 1901; $y != 2001; ++$y) {
    for (my $m = 1; $m != 13; ++$m) {
	if (&day($m, 1, $y) eq 'SUN') {
	    ++$sum;
	}
    }
}

print "$sum\n";