#include <fstream>
#include <string>

const int с = 2;

struct vector
{
    int size, n;
    int* vec;

    void init()
    {
        size = 1;
        n = 0;
        vec = new int[size];
    }

    void del()
    {
        delete[] vec;
    }

    /*void empty()
    {
        for (int i = 0; i < size; i++)
            vec[i] = 0;
    }

    void set(int i, int x)
    {
        vec[i] = x;
    }*/

    int get(int i)
    {
        return vec[i];
        n--;

        if (n < size / c)
            shrink();
    }

    void add(int x)
    {
        if (n > size)
        {
            int* new_vec = new int[с * size];

            for (int i = 0; i < size; i++)
                new_vec[i] = vec[i];

            del();
            vec = new_vec;
        }
        vec[n] = x;
        n++;
    }

    int shrink()
    {
        int* new_vec = new int[size / c];

        for (int i = 0; i < size / c; i++)
            new_vec[i] = vec[i];

        del();
        vec = new_vec;
    }
};

struct stack
{
    vector vec;

    void init()
    {
        vec.init();
    }

    void del()
    {
        vec.del();
    }

    void push(int x)
    {
        vec.add(x);
    }
    int pop()
    {
        return vec.get(vec.n);
    }
};

int main()
{
    std::fstream input("stack1.in");
    std::fstream output("stack1.out");

    stack s;
    s.init();
    int m;
    input >> m;
    std::string command;

    for (int i = 0; i < m; i++)
    {
        input >> command;

        if (command == "-") output << s.pop() << "\n";
        else
        {
            std::string t;
            input >> t;
            s.push(atoi(t.c_str()));
        }
    }
    s.del();

    return 0;
}