Hai just try this

$str='url Title: Mary moo-cow 856 invalid 
url Title: the mechanics 856 valid 
url Title: Mary moo-cow 858 invalid';

my @string =split/\n/, $str;

my @arr=();
for (@string)
{
if ($_ =~m#url Title:\s((.+?)\s(\d+)) invalid#gsi)
{
push(@arr,$1);
}
}

print "$_\n" for @arr;
[download]

output:

Mary moo-cow 856

Mary moo-cow 858