#include <bits/stdc++.h>
using namespace std;
string s;
int tip[2000005], w[2000005];
int st[2000005],dr[2000005];
pair<int,int> dp[2000005];
int p = 0;
void dfs(int nod)
{
if(tip[nod]==2)
{
dp[nod].first = 1;
dp[nod].second = 1;
w[nod] = 1;
return;
}
dfs(st[nod]);
w[nod] += w[st[nod]];
dfs(dr[nod]);
w[nod] += w[dr[nod]];
if(tip[nod]==0)
{
dp[nod].first = min(dp[st[nod]].first,dp[dr[nod]].first);
dp[nod].second = dp[st[nod]].second + dp[dr[nod]].second - 1;
}
else
{
dp[nod].first = dp[st[nod]].first + dp[dr[nod]].first;
dp[nod].second = max(w[st[nod]] + dp[dr[nod]].second, w[dr[nod]] + dp[st[nod]].second);
}
}
int nod = 1;
void eval()
{
if(s[p]=='?')
{
tip[nod] = 2;
++p;
return;
}
if(s[p+1]=='i')
{
tip[nod] = 0;
}
else
{
tip[nod] = 1;
}
p += 4;
int c_nod = nod;
st[c_nod] = (++nod);
eval();
++p;
dr[c_nod] = (++nod);
eval();
++p;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cin>>s;
nod = 1;
eval();
dfs(1);
cout<<dp[1].second - dp[1].first + 1<<'\n';
return 0;
}
