#include <bits/stdc++.h>
using namespace std;
typedef int64_t ll;
typedef string str;
int n, commas_gone;
str s;
vector <int> comma;
pair <int, int> get_range(int i) {
if (s[i] == '?') {
return {1, n};
} else if (s[i + 2] == 'x') {
pair <int, int> range_left = get_range(i + 4), range;
pair <int, int> range_right = get_range(comma[commas_gone++] + 1);
range.second = max(range_left.second, range_right.second);
range.first = range_left.first + range_right.first;
return range;
} else {
pair <int, int> range_left = get_range(i + 4), range;
pair <int, int> range_right = get_range(comma[commas_gone++] + 1);
range.second = range_left.second + range_right.second - n - 1;
range.first = min(range_left.first, range_right.first);
return range;
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> s;
for (int i = 0; i < (int)s.size(); ++i) {
if (s[i] == ',') {
comma.push_back(i);
}
}
n = count(s.begin(), s.end(), '?');
pair <int, int> range = get_range(0);
cout << range.second - range.first + 1;
}
