/* in the name of god */
/* be name khoda */
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define mp make_pair
#define fs first
#define cs second
#define be_fast ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define pii pair<ll, ll>
#define all_g(x) x.begin(), x.end(), greater<int>()
#define all(x) x.begin(), x.end()
const ll MAX_N = 1e4 + 24, mod1 = 998244353, mod2 = 1e9 + 7, lg = 21;
/// too gold . . .
/// is
string h;
vector<int>adj[MAX_N];
set<int>dp[MAX_N];
int mark[MAX_N];
vector<int>baga;
int cnt[MAX_N];
int dfs(int a){
if(h[a] == '?'){
baga.pb(a);
cnt[a] = 1;
return a;
}
h[a + 1] == 'i'? mark[a] = 1: mark[a] = 2;
adj[a].pb(a + 4);
int x = dfs(a + 4);
adj[a].pb(x + 2);
int xx = dfs(x + 2);
cnt[a] = cnt[a + 4] + cnt[x + 2];
return xx + 1;
}
void solve(int a){
if(h[a] == '?')
return;
for(int k : adj[a]){
solve(k);
}
int u = adj[a][0];
int v = adj[a][1];
if(mark[a] == 1){
for(int i = 1; i <= cnt[a]; i++){
auto x = (dp[u].upper_bound(i));
if(x == dp[u].begin())
continue;
x--;
int xx = *x;
auto p = dp[v].end(); p--;
int r = cnt[v] - *p + 1;
r += cnt[u] - xx;
if(r <= cnt[a] - i){
dp[a].insert(i);
}
}
for(int i = 1; i <= cnt[a]; i++){
auto x = (dp[v].upper_bound(i));
if(x == dp[v].begin())
continue;
x--;
int xx = *x;
auto p = dp[u].end(); p--;
int r = cnt[u] - *p + 1;
r += cnt[v] - xx;
if(r <= cnt[a] - i){
dp[a].insert(i);
}
}
}
else{
for(int i = 1; i <= cnt[a]; i++){
int x = *dp[v].begin();
x = i - x;
if(x < 0)continue;
auto p = dp[u].upper_bound(x);
if(p == dp[u].begin())
continue;
p--;
if(cnt[a] - i >= cnt[u] - *p){
dp[a].insert(i);
}
}
for(int i = 1; i <= cnt[a]; i++){
int x = *dp[u].begin();
x = i - x;
if(x < 0)continue;
auto p = dp[v].upper_bound(x);
if(p == dp[v].begin())
continue;
p--;
if(cnt[a] - i >= cnt[v] - *p){
dp[a].insert(i);
}
}
}
return;
}
int main(){
be_fast
cin >> h;
dfs(0);
for(int i : baga){
dp[i].insert(1);
}
solve(0);
cout << dp[0].size() << endl;
return 0;
}
