#!/usr/local/bin/perl -- # -*- Perl -*-

# 
# time_calc: 時間（時:分）の表現の演算
# 
#     Jan.20,'96. OSHIRO Naoki.
# 
#     $Log:$
#

while (<>) {
    while (/([0-9]+):([0-9]+)/) {
	$_="$`" . ($1*60+$2) . "$'";
    }
    $_=eval($_);
    $hour=int($_/60);
    $min=$_-$hour*60;
    printf "$hour:%02d\n", $min;
}