#include <bits/stdc++.h>
using namespace std;
struct Node {
int l = -1, r = -1;
char op = '?';
};
string s;
int pos = 0;
vector<Node> tree;
int parse() {
int id = tree.size();
tree.push_back(Node());
if (s[pos] == '?') {
tree[id].op = '?';
pos++;
return id;
}
if (s[pos] == 'm' && s[pos + 1] == 'i') {
tree[id].op = 'm';
pos += 4;
}
else {
tree[id].op = 'M';
pos += 4;
}
tree[id].l = parse();
pos++;
tree[id].r = parse();
pos++;
return id;
}
struct tr {
int L, R, sz;
};
tr dfs(int v) {
if (tree[v].op == '?') {
return {1, 1, 1};
}
tr a = dfs(tree[v].l);
tr b = dfs(tree[v].r);
tr res;
res.sz = a.sz + b.sz;
if (tree[v].op == 'm') {
res.L = min(a.L, b.L);
res.R = a.R + b.R - 1;
}
else {
res.L = a.L + b.L;
res.R = max(a.R + b.sz, b.R + a.sz);
}
return res;
}
void solve() {
cin >> s;
pos = 0;
tree.clear();
int root = parse();
tr ans = dfs(root);
cout << ans.R - ans.L + 1 << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
return 0;
}
