#include<bits/stdc++.h>
using namespace std;
int len,maxx=-1,lon;
string s;
stack<char> ch1,ch2,ch3;
int main(){
	cin>>s;
	len=s.length();
	for(int i=0;i<len;i++){
		lon=0;
		while(!ch1.empty()){
			ch1.pop();
		}
		while(!ch2.empty()){
			ch2.pop();
		}
		while(!ch3.empty()){
			ch3.pop();
		}
		for(int j=i;j<len;j++){
			if(s[j]==')'){
				if(ch1.empty())
				    break;
				if(!ch2.empty()&&ch2.top()>ch1.top())
				    break;
				if(!ch3.empty()&&ch3.top()>ch1.top())
				    break;
			}
			if(s[j]==']'){
				if(ch2.empty())
				    break;
				if(!ch1.empty()&&ch1.top()>ch2.top())
				    break;
				if(!ch3.empty()&&ch3.top()>ch2.top())
				    break;
			}
			if(s[j]=='}'){
				if(ch3.empty())
				    break;
				if(!ch2.empty()&&ch2.top()>ch3.top())
				    break;
				if(!ch1.empty()&&ch1.top()>ch3.top())
				    break;
			}
			if(s[j]=='(') 
			    ch1.push(j);
			if(s[j]==')') 
			    ch1.pop();
			if(s[j]=='[') 
			    ch2.push(j);
			if(s[j]==']') 
			    ch2.pop();
			if(s[j]=='{') 
			    ch3.push(j);
			if(s[j]=='}') 
			    ch3.pop();
			if(ch1.empty()&&ch2.empty()&&ch3.empty()) 
			    lon=j-i+1;
		}
		maxx=max(maxx,lon);
	}
	cout<<maxx;
	return 0;
}