#include <iostream>
#include <string>
#include <vector>

using namespace std;

void main()
{
	vector<string> test;
	string str[10] = {"textbook", "title", "/title", "/textbook"};

	
	
	int count = 0;
	test.push_back(str[count++]);
	while ()
	{
		if (str[count].at(0) == '/' && str[count].substr(1) == test[test.size()-1])
		{test.pop_back();}	
		else
		{
			test.push_back(str[count]);
			//cout << "count == " << count << endl;		
			//cout << test[count] << endl;
		}
		
		count++;	
	}
	if (test.size() != 0)
		cout << test.size() << "errors" << endl;


}