#include <bits/stdc++.h>
#define int long long
using namespace std;
using pii = pair<int, int>;
using t3i = tuple<int, int, int>;
struct Node {
Node *l = nullptr, *r = nullptr, *p = nullptr;
bool fmin, atom;
int le, ge;
Node() {}
int parse(string &s, int cursor, vector<Node*> &atoms) {
if (s[cursor] == '?') {
atom = 1;
atoms.push_back(this);
return cursor + 1;
} else {
atom = 0;
fmin = s[cursor + 2] == 'n';
l = new Node(), r = new Node();
l->p = this, r->p = this;
cursor = l->parse(s, cursor + 4, atoms);
return r->parse(s, cursor + 1, atoms) + 1;
}
}
void run() {
if (atom) {
le = ge = 1;
} else {
l->run();
r->run();
if (fmin) {
le = min(l->le, r->le);
ge = l->ge + r->ge;
} else {
le = l->le + r->le;
ge = min(l->ge, r->ge);
}
}
}
};
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0);
string s;
cin >> s;
vector<Node*> atoms;
Node *root = new Node();
root->parse(s, 0, atoms);
int n = atoms.size();
root->run();
cout << n + 2 - root->le - root->ge << "\n";
}
