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