#include <vector>
#include <iostream>
#include <string>
#include <sstream>
using namespace std;
int main(){
    string s;
	cin>>s;
	vector<string> ans;
	for(int i=0;i<s.size();i++){
		if(s[i]>='a' and s[i]<='z'){
			stringstream sin;
			sin<<s[i];
			string item ;
			sin>>item;
			ans.push_back(item);
		}
		else{
			string a=ans[ans.size()-1];
			ans.pop_back();
			string b=ans[ans.size()-1];
			ans.pop_back();
			ans.push_back("("+a+" "+s[i]+" "+b+")");
		}
	}
	cout<<ans[0]<<endl;
	return 0;
}