krsu 3405 (55 points)

/*
by: senb1 aka amigo
*/

#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
#define all(x) x.begin(), x.end()
#define endl '\n'

const ll maxn = 50;
const ll inf = 5e5 + 6;
const ll mod = 2021;

int main() {
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);

    string s;
    cin >> s;
    int b = 0, ans = 0, ind = 0;
    for (int i = 0; i < s.size(); i++) {
        if (s[i] == '(') {
            b++;
            // cout << "B++!! " << b << endl;
        } else if (s[i] == ')') {
            b--;
            ind = i;
        } else if (s[i] == 'X')
            continue;
        else
            continue;
        if (b < 0) {
            // cout << "b < 0 " << b << ' ' << ind << endl;
            int jj = 0;
            for (int j = ind; j < s.size(); j++)
                if (s[j] == '(') {
                    jj = j;
                    break;
                }
            while (jj > ind) {
                swap(s[jj], s[jj - 1]);
                jj--;
                ans++;
            }
            swap(s[jj], s[jj + 1]);
        }
        // cout << i << ' ' << b << ' ' << s << ' ' << ans << endl;
    }
    cout << ans << endl;
}
/*
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()))((
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()()()
*/