You can use this..

#! /bin/perl -w
use strict;

my @a = qw ( server1 server2 server3 server5 );

my @b=();

my @c=();

open(FILE,"file") or die "$!\n";
@b=<FILE>;
close FILE;

chomp(@b);

print "a list is @a\n";
print "b list is @b\n";

foreach my $server (@b)
{
        if( ! grep(/$server/,@a))
        {
                push(@c,$server);
        }
}

print "c list is @c\n";
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