#!/usr/bin/perl

use strict;
use warnings;

use Time::Piece;
use Time::Seconds;

my $t1 = Time::Piece->strptime("16:51", "%M:%S");
my $t2 = Time::Piece->strptime("34:48", "%M:%S");

$t1 += $t2->min*60 + $t2->sec;

print $t1->strftime("%M:%S");