#include<bits/stdc++.h>
using namespace std;
stack<char>st;
int main(){
	string s;
	cin>>s;
	int ans=-1;
	for(int i=0;i<s.size();i++){
		int cnt=0;
		while(!st.empty()) st.pop();
		if(s[i]==')'||s[i]==']'||s[i]=='}') continue;
		for(int j=i;j<s.size();j++){
			if(s[j]=='('||s[j]=='['||s[j]=='{'){
				st.push(s[j]);
			}
			else{
				char c=' ';
				if(!st.empty()) c=st.top(),st.pop();
				if((c=='('&&s[j]==')') || (c=='['&&s[j]==']') || (c=='{'&&s[j]=='}')){
					cnt+=2;
				}
				else break;
			}
		}
		ans=max(ans,cnt); 
	}
	cout<<ans;
	return 0;
}