#!/usr/bin/perl -w

my (@line, $brack, $diff, $num);

while (<>) {
	$num++;
	if ($diff = y/{/{/ - y/}/}/) {
		$brack += $diff;
		$line[$brack] = $num if ($diff > 0);
	}
}

print ($brack > 0 ? "Error at line $line[$brack]?\n" : "No bracket errors found.\n");