use strict;
my $str = ' 25д10ч3м10с
25д0ч3м10с
15м30с
10д5с
10ч
15м
30с
25д3м11с';
my $regex = qr/(\d+д)?(\d+ч)?(\d+м)?(\d+с)?/ip;
my $subst = '';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html