#include <iostream>
#include <cmath>
#include <math.h>
#include <vector>
#include <algorithm>
#include <string>
#include <numeric>
#define int long long
using namespace std;
const int INF = 100000000000000;
const int SIZE = 200200;
int a[SIZE];
int t[4 * SIZE];
int sum = 0;
int ans = 0;


inline void build(int v, int l, int r) {
    if (r - l == 1) {
        t[v] = a[l];
        return;
    }
    int m = (l + r) / 2;
    build(2 * v + 1, l, m);
    build(2 * v + 2, m, r);
    t[v] = t[2 * v + 1] + t[2 * v + 2];
}

inline void find(int v, int l, int r, int pos) {
    if (r - l == 1)
        return;
    int m = (l + r) / 2;
    if (pos < m) {
        sum += t[2 * v + 2];
        find(2 * v + 1, l, m);
    }
    else {
        find(2 * v + 2, m, r);
    }
}

inline void ask(int v, int l, int r, int val) {
    if (r - l == 1) {
        ans = r;
        return;
    }
    int m = (l + r) / 2;
    if (t[2 * v + 1] >= val) {
        ask(2 * v + 1, l, m, val);
    }
    else {
        ask(2 * v + 2, m, r, val - t[2 * v + 1]);
    }
}

inline void change(int v, int l, int r, int pos) {
    if (r - l == 1) {
        t[v] = 1 - t[v];
        return;
    }
    int m = (l + r) / 2;
    if (pos < m) {
        change(2 * v + 1, l, m, pos);
    }
    else {
        change(2 * v + 2, m, r, pos);
    }
    t[v] = t[2 * v + 1] + t[2 * v + 2];
}


void solve() {
    for (int i = 0; i < SIZE; i++) {
        a[i] = 1;
    }
    int m; cin >> m;
    vector<int> q(m);
    build(0, 0, SIZE);
    for (int i = 0; i < m; i++)
        cin >> q[i];
    for (int i = 0; i < m; i++) {
        if (q[i] > 0) {
            find(0, 0, SIZE, q[i] - 1);
            int ths = t[0] - sum;
            sum = 0;
            ask(0, 0, SIZE, ths);
            cout << ans << "\n";
            ans = 0;
            change(0, 0, SIZE, q[i] - 1);
        }
        else {
            change(0, 0, SIZE, abs(q[i]) - 1);
        }
    }
}

signed main() {
    //freopen("rvq.in", "r", stdin);
    //freopen("rvq.out", "w", stdout);
    cin.tie(0);
    cout.tie(0);
    solve();
}