#include <bits/stdc++.h>

#define sz(v) (int)v.size()
#define pb push_back

using namespace std;

class Node {
public:
    int value;
    Node *next;

public:
    Node(int value) {
        this->value = value;
        this->next = NULL;
    }
};

class List {
public:
    Node *head, *tail;
public:
    List() {
        this->head = this->tail = NULL;
    }

    void pop_front() {
        if (head == NULL) cout << "error\n";
        else if (head == tail) {
            cout << head->value << '\n';
            delete tail;
            head = tail = NULL;
        } else {
            cout << head->value << '\n';
            Node *node = head;
            head = node->next;
            delete node;
        }
    }

    void push_back(int value) {
        Node *node = new Node(value);
        if (head == NULL) head = node;
        if (tail != NULL) tail->next = node;
        tail = node;
    }
};


class Queue {
private:
    List Node;
    int size;
public:

    Queue() {
        size = 0;
    }

    int Queue_size() {
        return size;
    }

    void put(int num) {
        Node.push_back(num);
        size++;
    }

    void get() {
        Node.pop_front();
        if(size != 0){
            size--;
        }
    }

};

int main() {
    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    int t;
    cin >> t;
    Queue queue;
    while (t--) {
        string input;
        cin >> input;
        if (input == "put") {
            int q;
            cin >> q;
            queue.put(q);
        } else if (input == "size") {
            cout << queue.Queue_size() << '\n';
        } else {
            queue.get();
        }
    }

}