Imanol-Mikel Barba Sabariego / jutge · Files

#include <iostream>

using namespace std;

int main()
{
	char c;
	int score = 0;
	while(true)
	{
		cin >> c;
		if(cin.eof())
		{
			break;
		}
		if(c == '(')
		{
			score++;
		}
		else if(c == ')')
		{
			if(--score < 0)
			{
				cout << "no" << endl;
				return 0;
			}
		}
	}
	if(score)
	{
		cout << "no" << endl;
		return 0;
	}
	cout << "yes" << endl;
	return 0;
}