#!/usr/bin/env perl use strict; use warnings; my ($n, $m) = split / /,<>; chomp $m; my ($f1, $f2) = (0, 1); my $f3; for (my $i = 2; $i < $n; $i++) { $f3 = ($f1 + $f2) % $m; $f1 = $f2; $f2 = $f3; } print $f3;