#include <bits/stdc++.h>
using namespace std;
string s;
vector<int> comma;
int solve(int l, int r, bool greater) {
if (s[l] == '?') return 1;
int i = comma[l + 3];
int x = solve(l + 4, i - 1, greater), y = solve(i + 1, r - 1, greater);
if (greater) {
if (s[l + 1] == 'a') return min(x, y);
else return x + y;
} else {
if (s[l + 1] == 'a') return x + y;
else return min(x, y);
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> s;
int n = (int) s.length();
stack<int> st;
comma.assign(n, -1);
for (int i = 0; i < n; i++) {
if (s[i] == '(') st.push(i);
if (s[i] == ')') st.pop();
if (s[i] == ',') comma[st.top()] = i;
}
int cnt = 0;
for (int i = 0; i < n; i++) if (s[i] == '?') cnt++;
int mx = cnt - solve(0, n - 1, true) + 1, mn = solve(0, n - 1, false);
cout << mx - mn + 1 << '\n';
return 0;
}
