#include <bits/stdc++.h>
using namespace std;
vector<int> graph[2000001];
int par[2000001], n = 0, type[2000001], sz[2000001], mn[2000001], mx[2000001];
void dfs( int i){
if( !graph[i].size()) return;
int u = graph[i][0], v = graph[i][1];
dfs(u);
dfs(v);
sz[i] += sz[u] + sz[v];
if( type[i] == 1){
mn[i] = min( mn[u], mn[v]);
mx[i] = mx[u] + mx[v] - 1;
}
else if( type[i] == 2){
mn[i] = mn[u] + mn[v];
mx[i] = max( sz[u] + mx[v], sz[v] + mx[u]);
}
}
int main() {
string s;
cin >> s;
int curr = 0;
for( int i = 0; i < s.size(); i++){
if( s[i] == 'm'){
n++;
par[n] = curr;
graph[curr].push_back(n);
curr = n;
if( s[i + 2] == 'n') type[curr] = 1;
else type[curr] = 2;
i+=3;
}
else if( s[i] == '?'){
n++;
graph[curr].push_back(n);
curr = n;
mn[curr] = mx[curr] = sz[curr] = 1;
} else {
curr = par[curr];
}
}
dfs(1);
cout << mx[1] - mn[1] + 1;
return 0;
}
