#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
string n;
cin >> n;
vector<int> p;
vector<vector<int>> c;
vector<int> t;
stack<int> curp;
int node=0, count=0;
curp.push(0);
p.push_back(0);
c.push_back(vector<int>(0));
if(n[2]=='x') t.push_back(0);
else t.push_back(1);
for(int i=3; i<n.size(); i++)
{
if(n[i]==')') curp.pop();
else if(n[i]=='x')
{
node++;
p.push_back(curp.top());
c.push_back(vector<int>(0));
c[curp.top()].push_back(node);
t.push_back(0);
curp.push(node);
}
else if(n[i]=='n')
{
node++;
p.push_back(curp.top());
c.push_back(vector<int>(0));
c[curp.top()].push_back(node);
t.push_back(1);
curp.push(node);
}
else if(n[i]=='?') count++;
}
queue<int> q;
for(int i=0; i<=node; i++)
{
if(c[i].size()==0) q.push(i);
}
vector<bool> seen(node+1, false);
vector<vector<int>> val(node+1, vector<int>(2, 0));
while(!q.empty())
{
int v=q.front();
q.pop();
if(seen[v]) continue;
bool sc=true;
for(auto child : c[v])
{
if(!seen[child]) sc=false;
}
if(!sc) continue;
val[v][t[v]]+=1;
if(c[v].size()==2) val[v][(t[v]+1)%2]=min(val[c[v][0]][(t[v]+1)%2], val[c[v][1]][(t[v]+1)%2]);
for(auto child : c[v])
{
val[v][t[v]]+=val[child][t[v]];
}
seen[v]=true;
if(p[v]!=v) q.push(p[v]);
}
cout << count-(val[0][0]+val[0][1]) << '\n';
}
