/*
 * RMID.cpp
 *
 *  Created on: Aug 14, 2014
 *      Author: Arpit Bhayani
 */

#include <map>
#include <set>
#include <cstring>
#include <stack>
#include <vector>
#include <queue>
#include <list>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <climits>

using namespace std;

#define si(x) scanf("%d" , &x)
#define sl(x) scanf("%ld" , &x)
#define sll(x) scanf("%lld" , &x)
#define sc(x) scanf("%c" , &x)
#define ss(x) scanf("%s" , &x)

#define pi(x) printf("%d\n" , x)
#define pl(x) printf("%ld\n" , x)
#define pll(x) printf("%lld\n" , x)
#define pc(x) printf("%c\n" , x)
#define ps(x) printf("%s\n" , x)

#define fup(i,a,b) for(int i=a;i<b;i++)
#define fdn(i,a,b) for(int i=a;i>=b;i--)

#define DEBUG 0
#define gc getchar
#define ll long long

void scanint(ll int &x) {
    register ll int c = gc();
    x = 0;
    for (; (c < 48 || c > 57); c = gc())
        ;
    for (; c > 47 && c < 58; c = gc()) {
        x = (x << 1) + (x << 3) + c - 48;
    }
}

int readline(char * str) {

    int i = 0;
    char ch;
    while ((ch = getchar()) != '\n') {
        str[i++] = ch;
    }
    str[i] = '\0';
    return i;
}

#define ASIZE 10

struct minheapcomparator {
    bool operator()(int i, int j) {
        return i > j;
    }
};

priority_queue<int> l;
priority_queue<int, vector<int>, minheapcomparator> r;

int check_size() {
    if (l.size() == r.size())
        return 0;
    if (l.size() > r.size()) {
        return -1;
    } else {
        return 1;
    }
}

void get_median(int &med) {

    int c = check_size();

    switch (c) {

    case 0:

        med = l.top();
        l.pop();
        break;

    case -1:

        med = l.top();
        l.pop();

        break;
    case 1:

        med = r.top();
        r.pop();

        break;
    }

}

void median(int current_element, int &med) {

    int c = check_size();

    switch (c) {
    case 0:

        if (current_element < med) {
            l.push(current_element);
            med = l.top();
        } else {
            r.push(current_element);
            med = r.top();
        }

        break;
    case -1:

        if (current_element < med) {
            int t = l.top();
            l.pop();
            r.push(t);

            l.push(current_element);

            med = l.top();
        } else {
            r.push(current_element);
            med = l.top();
        }

        break;
    case 1:

        if (current_element < med) {
            l.push(current_element);
            med = l.top();
        } else {

            int t = r.top();
            r.pop();
            l.push(t);

            r.push(current_element);
            med = l.top();

        }

        break;
    }

}

int main(int argc, char * argv[]) {

    int x;
    int med = 0;

    while ( si(x) != EOF ) {

        if (x == 0) {

            while (!l.empty())
                l.pop();

            while (!r.empty())
                r.pop();

            pc('\n');
        }

        else if (x == -1) {

            get_median(med);
            pi(med);

        }

        else {

            median(x, med);

        }

    }

    return 0;
}