#include <bits/stdc++.h>
using namespace std;
string a;
int poz;
int curnod = 1;
int l[4000005],r[4000005],s[4000005];
int fs[4000005],fd[4000005],tip[4000005];
void build_tree(int nod)
{
if (a[poz] != '?')
{
if (a[poz + 1] == 'i')
tip[nod] = 0;
else
tip[nod] = 1;
poz += 4;
curnod++;
fs[nod] = curnod;
build_tree(curnod);
poz++;
curnod++;
fd[nod] = curnod;
build_tree(curnod);
poz++;
}
else
{
tip[nod] = -1;
fs[nod] = fd[nod] = -1;
poz++;
}
}
void dfs(int nod)
{
if (fs[nod] == -1)
l[nod] = r[nod] = s[nod] = 1;
else
{
dfs(fs[nod]);
dfs(fd[nod]);
s[nod] = s[fs[nod]] + s[fd[nod]];
if (tip[nod] == 0)
{
l[nod] = min(l[fs[nod]],l[fd[nod]]);
r[nod] = r[fs[nod]] + r[fd[nod]] - 1;
}
else
{
l[nod] = l[fs[nod]] + l[fd[nod]];
r[nod] = max(l[fs[nod]] + s[fd[nod]],l[fd[nod]] + s[fs[nod]]);
}
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> a;
build_tree(1);
dfs(1);
cout << r[1] - l[1] + 1;
return 0;
}
/**
Construiesc arborele ala
Fiecare nod poate avea un interval
Daca e frunza, e L = R = S = 1
Fie L1 R1 S1 si L2 R2 S2 L,R si size-ul pentru fii
S = S1 + S2 oricum
Daca e nod de min, L = min(L1,L2), R = R1 + R2 - 1
Daca e nod de max, L = L1 + L2 + 1, R = max(L1 + S2,L2 + S1)
**/
