#include <bits/stdc++.h>
using namespace std;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    deque<int> deq[150001];
    int m, n, x;
    string o;
    cin>>m;
    for(int i = 0; i < m; i++){
        cin>>o>>n;
        if(o == "pushfront"){
            cin>>x;
            deq[n].push_front(x);

        }
        else if(o == "pushback"){
            cin>>x;
            deq[n].push_back(x);
        }
        else if(o == "popfront"){
            cout<<deq[n].front()<<endl;
            deq[n].pop_front();

        }
        else{
            cout<<deq[n].back()<<endl;
            deq[n].pop_back();
        }
    }
    return 0;
}

include <iostream>

include <deque>

include <vector>

include <string>

using namespace std;

const int MAX_DEQUES = 150000;

int main() { ios::syncwithstdio(false); cin.tie(nullptr);

vector<deque<int>> deques(MAX_DEQUES + 1);

int n;
cin >> n;

for (int i = 0; i < n; ++i) {
    string op;
    int a, b;
    cin >> op >> a;
    if (op == "pushfront") {
        cin >> b;
        deques[a].push_front(b);
    } else if (op == "pushback") {
        cin >> b;
        deques[a].push_back(b);
    } else if (op == "popfront") {
        cout << deques[a].front() << endl;
        deques[a].pop_front();
    } else if (op == "popback") {
        cout << deques[a].back() << endl;
        deques[a].pop_back();
    }
}

return 0;

}