#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
str s;
int n = 1, m;
vector<int> type(1, -1);
vector<int> L(1, -1), R(1, -1);
vector<int> leaves;
vector<vector<int>> dp;
vector<int> sum;
int create_tree(int nd, int i){
if(s[i] == '?'){
leaves.pb(nd);
return i;
}
if(s[i+1] == 'i') type[nd] = 0;
else type[nd] = 1;
L.pb(-1);
R.pb(-1);
type.pb(-1);
L[nd] = n;
n++;
int x = create_tree(L[nd], i+4);
x+=2;
L.pb(-1);
R.pb(-1);
type.pb(-1);
R[nd] = n;
n++;
x = create_tree(R[nd], x);
return x+1;
}
void pre_dfs(int nd){
if(type[nd] == -1){
dp[nd][0] = 1;
dp[nd][1] = 1;
return;
}
pre_dfs(L[nd]);
pre_dfs(R[nd]);
// want smaller (dp[nd][0])
if(type[nd] == 0) dp[nd][0] = min(dp[L[nd]][0], dp[R[nd]][0]);
else dp[nd][0] = dp[L[nd]][0] + dp[R[nd]][0];
// want larger (dp[nd][1])
if(type[nd] == 0) dp[nd][1] = dp[L[nd]][1] + dp[R[nd]][1];
else dp[nd][1] = min(dp[L[nd]][1], dp[R[nd]][1]);
}
void dfs(int nd, int a = 0, int b = 0){
if(type[nd] == -1){
if(a+b < m) sum[a]++, sum[m-b]--;
return;
}
if(type[nd] == 0){
dfs(L[nd], a, b+dp[R[nd]][1]);
dfs(R[nd], a, b+dp[L[nd]][1]);
}
else{
dfs(L[nd], a+dp[R[nd]][0], b);
dfs(R[nd], a+dp[L[nd]][0], b);
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> s;
create_tree(0, 0);
dp.assign(n, vector<int>(2, n));
m = leaves.size();
sum.assign(m+1, 0);
pre_dfs(0);
dfs(0);
int ans = 0;
for(int i = 0; i < m; i++){
if(i) sum[i]+=sum[i-1];
if(sum[i] > 0) ans++;
}
cout << ans << "\n";
}
