my $found_first  = 0;
my $found_second = 0;
while (<LOG>) {
    if (/002389983/) {
        print "Looking for: 002389983\n Found it in file: $_\n";
        $found_first = 1;
        last;
    }
}
if ($found_first) {
    seek LOG, 0, 0;
    while (<LOG>) {
        if (/002389983/) {
            print "Looking for: 29994339499\n Found it in file: $_\n";
            $found_second = 1;
            last;
        }
    }
}
unless ($found_second) {
    print "Could not find the second string: 29994339499\n";
}