/* Topcoder SRM 688, D2, 250-pointer: ParenthesesDiv2Easy
 * James S. Plank
 * Tue Sep  6 00:42:57 EDT 2016
 */

#include <string>
#include <vector>
#include <list>
#include <cmath>
#include <algorithm>
#include <map>
#include <set>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

class ParenthesesDiv2Easy
{
    public:
        int getDepth(string s);
};

int ParenthesesDiv2Easy::getDepth(string s)
{
    int i;    /* We will use i to run through s from left to right. */
    int p;    /* P will be our counter that records the depth at s[i]. */
    int rv;   /* This is our return value -- the max depth. */

    rv = 0;
    p = 0;

    /* Increment p when you encounter a left paren,
       and record the maximum depth. 
       Decrement p when you encounter a right paren. */

    for (i = 0; i < s.size(); i++) {
        if (s[i] == '(') {
            p++;
            if (p > rv) rv = p;
        } else {
            p--;
        }
    }

    return rv;
}