#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define mk make_pair
#define endl '\n'
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int N = 2e6 + 50;
int n;
string s;
pii ch[N];
bool mark[N];
int cnt[N];
pii dp[N];
stack<int> st;
void input() {
cin >> s;
for (int i = 0; i < (int)s.size(); i++) {
if (s[i] == 'm') {
n++;
st.push(n);
mark[n] = (s[i+1] == 'a');
i += 3;
continue;
}
else if (s[i] == '?') {
n++;
if (st.empty()) continue;
if (ch[st.top()].F) ch[st.top()].S = n;
else ch[st.top()].F = n;
}
else if (s[i] == ')') {
int u = st.top();
st.pop();
if (st.empty()) continue;
if (ch[st.top()].F) ch[st.top()].S = u;
else ch[st.top()].F = u;
}
}
}
void dfs(int u) {
if (!ch[u].F) return;
int v1 = ch[u].F, v2 = ch[u].S;
dfs(v1);
dfs(v2);
dp[u].F = (mark[u]? dp[v1].F + dp[v2].F + 1: min(dp[v1].F, dp[v2].F));
dp[u].S = (mark[u]? min(dp[v1].S, dp[v2].S): dp[v1].S+dp[v2].S+1);
}
void solve() {
input();
dfs(1);
cout << (n+1)/2 - dp[1].F - dp[1].S << endl;
}
int main() {
ios::sync_with_stdio(0), cin.tie(0);
solve();
return 0;
}
