#include <iostream>
#include <string>
using namespace std;
struct node{
int l, r, n;
bool min = false;
bool max = false;
bool num = false;
int min_v, max_v;
node* s1 = nullptr;
node* s2 = nullptr;
};
string s;
node* read(int l){
node* ans = new node;
ans->l = l;
if(s[l] == '?'){
ans->num = true;
ans->r = l+1;
ans->n = 1;
} else {
ans->s1 = read(l+4);
ans->s2 = read(ans->s1->r+1);
ans->r = ans->s2->r+1;
ans->n = ans->s1->n + ans->s2->n;
if(s[l+1] == 'i'){
ans->min = true;
} else {
ans->max = true;
}
}
//cout << "My left is " << ans->l << ", my right is " << ans->r << " max: " << ans->max << endl;
return ans;
}
void eval(node* root){
if(root->num) {
root->min_v = 0;
root->max_v = 0;
return;
} else {
eval(root->s1);
eval(root->s2);
if(root->min){
root->min_v = min(root->s1->min_v, root->s2->min_v);
root->max_v = root->s1->max_v + root->s2->max_v + 1;
} else {
root->min_v = root->s1->min_v + root->s2->min_v + 1;
root->max_v = min(root->s1->max_v, root->s2->max_v);
}
}
}
int main(){
cin >> s;
node *root = read(0);
eval(root);
cout << root->n - root->min_v - root->max_v << endl;
return 0;
}
