#include<bits/stdc++.h>
#include<fstream>
using namespace std;
#define sz(a) (int)a.size()
#define ALL(v) v.begin(), v.end()
#define ALLR(v) v.rbegin(), v.rend()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mpp make_pair
#define ull unsigned long long
const ld PI = 3.14159265359, prec = 1e-9;;
//using u128 = __uint128_t;
//const int x[4] = {1, 0, -1, 0};
//const int y[4] = {0, -1, 0, 1};
const ll mod = 1e9 + 19972207, pr = 31;
const int mxn = 3e5 + 5, mxq = 1e5 + 5, sq = 105, mxv = 64;
//const int base = (1 <<18);
const ll inf = 1e9, neg = -69420, inf2 = 1e14;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// have fun
int n;
int a[mxn + 1], pa[mxn + 1], level[mxn + 1];
bool active[mxn + 1];
void solve(){
cin >> n;
for(int i = 1; i <= n; i++){
cin >> a[i];
}
active[0] = 1;
for(int i = 1; i <= n; i++){
active[i] = 1;
if(a[i] > 0){
pa[i] = -1;
cout << a[i] << "\n";
level[i] = 0;
continue;
}else{
level[i] = -a[i];
for(int j = i - 1; j >= 1; j--){
if(active[j] && level[j] < level[i]){
pa[i] = j;
break;
}
}
for(int j = pa[i]; j != -1; j = pa[j]){
active[j] ^= 1;
}
for(int j = i - 1; j >= 0; j--){
if(active[j] && level[j] == 0){
cout << a[j] << "\n";
break;
}
}
}
}
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//freopen("TRILAND.inp", "r", stdin);
//freopen("TRILAND.out", "w", stdout);
int tt; tt = 1;
while(tt--){
solve();
}
return(0);
}
