#include <bits/stdc++.h>
using namespace std;

int main() {
	stack <int> P;
	int n, num, v1, v2;
	string accion;
	
	cin >> n;
	for( int i=1;i<=n;i++){
		cin >> accion;
		if(accion == "AGREGA"){	cin >> num; P.push(num);}
		else if (accion == "CONSUME"){
			v1=P.top(); P.pop();
			v2=P.top(); P.pop();
			P.push(v1+v2);
			}
		
		else{
			cout << P.top() << "\n";
	}
	}
	return 0;
}