#include <bits/stdc++.h>
using namespace std;
void setup()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
int x = 0, n;
string s;
pair<int, int> p;
inline pair<int, int> Form()
{
pair<int, int> l, r;
if (s[x] == '?')
{
return {1, n};
}
x++;
char o = s[x];
x += 3;
l = Form();
x += 2;
r = Form();
x++;
if (o == 'i')
{
return {min(l.first, r.first), l.second + r.second - n - 1};
}
return {l.first + r.first, max(l.second, r.second)};
}
int main()
{
setup();
cin >> s;
n = count(s.begin(), s.end(), '?');
p = Form();
cout << p.second - p.first + 1;
return 0;
}
