#include <bits/stdc++.h>

using namespace std;

int mod = 1e9;

struct Node{
    Node *left, *right;
    int y = rand(), x;
};

vector<Node> tree(200000);
int POS = 0;

void split(Node *treap, Node *&left, Node *&right, int x){
    if (treap == NULL){
        left = right = NULL;
        return;
    }
    if (treap->x < x){
        left = treap;
        split(treap->right, treap->right, right, x);
    }
    else{
        right = treap;
        split(treap->left, left, treap->left, x);
    }
}

void merge(Node *&treap, Node *left, Node *right){
    if (left == NULL){
        treap = right;
        return;
    }
    if (right == NULL){
        treap = left;
        return;
    }
    if (left->y > right->y){
        treap = left;
        merge(treap->right, treap->right, right);
    }
    else{
        treap = right;
        merge(treap->left, left, treap->left);
    }
}

void out(Node *treap){
    if (treap == NULL)
        return;
    out(treap->left);
    cout << treap->x << " ";
    out(treap->right);
}

int get(Node *treap){
    if (treap->left == NULL)
        return treap->x;
    return get(treap->left);
}

int main(){
//    freopen("swapper.in", "r", stdin);
//    freopen("swapper.out", "w", stdout);
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int n, x, prev = 0;
    cin >> n;

    char act;
    Node *treap = NULL;
    Node *left, *right;
    for (int i = 0; i < n; i++){
        cin >> act >> x;
        if (act == '+'){
            x = (x + prev) % mod;
            prev = 0;
            split(treap, left, right, x);
            if (right == NULL || get(right) != x){
                tree[POS].x = x;
                Node *mid = &tree[POS++];
                merge(treap, left, mid);
                merge(treap, treap, right);
            }
            else merge(treap, left, right);
        }
        else{
            split(treap, left, right, x);
            if (right == NULL)
                prev = -1;
            else
                prev = get(right);
            merge(treap, left, right);
            cout << prev << "\n";
        }
//        cout << "i: " << i << endl;
//        out(treap); cout << endl;
    }
    return 0;
}