#include <bits/stdc++.h>
using namespace std;
const int N = 3e5+5;
struct node {
int val;
node *l, *r;
node(int val, node *l, node *r) : val(val), l(l), r(r) {}
};
node* newleaf(int val) { return new node(val, NULL, NULL); }
node* newpar(node *l, node *r) { return new node(min(l->val, r->val), l, r); }
int n, ans[N];
node* t[N];
node* build(int l = 1, int r = n) {
if(l == r) return newleaf(N);
int mid = (l + r) >> 1;
return newpar(build(l, mid), build(mid+1, r));
}
node* update(int x, int k, node *p, int l = 1, int r = n) {
if(x < l || r < x) return p;
if(l == r) return newleaf(k);
int mid = (l + r) >> 1;
return newpar(update(x, k, p->l, l, mid), update(x, k, p->r, mid+1, r));
}
int find(int x, node *p, int l = 1, int r = n) {
if(l == r) return l;
int mid = (l + r) >> 1;
if(p->r->val < x) return find(x, p->r, mid+1, r);
else return find(x, p->l, l, mid);
}
int main() {
scanf("%d", &n);
t[0] = build();
for(int i = 1, a; i <= n; i++) {
scanf("%d", &a);
if(a > 0) {
ans[i] = a;
t[i] = update(i, 0, t[i-1]);
} else {
int pre = find(-a, t[i-1]) - 1;
ans[i] = ans[pre];
t[i] = update(i, -a, t[pre]);
}
printf("%d\n", ans[i]);
}
return 0;
}
