#include <algorithm>
#include <cmath>
#include <iostream>
#include <map>
#include <string>
#include <vector>
#include <set>
#include <unordered_map>

using namespace std;

int  find_distance(const set<int>& reachable_stations, int finish) {
    if (reachable_stations.size() == 1) {
        return abs(finish - *reachable_stations.begin());
    }

    auto it = lower_bound(reachable_stations.begin(), reachable_stations.end(), finish);
    if (it == reachable_stations.end()) {
        return abs(finish - *(--it));
    }
    if (it == reachable_stations.begin()) {
        return abs(finish - *it);
    }
    return min(abs(finish - *it), abs(finish - *(it--)));
}

class RouteManager {
public:
    void AddRoute(int start, int finish) {
        reachable_lists_[start].insert(finish);
        reachable_lists_[finish].insert(start);
    }
    int FindNearestFinish(int start, int finish) const {
        int result = abs(start - finish);
        auto it = reachable_lists_.find(start);
        if (it == reachable_lists_.end()) {
            return result;
        }
        const set<int>& reachable_stations = it->second;
        if (!reachable_stations.empty()) {
            result = min( result, find_distance(reachable_stations, finish));
        }
        return result;
    }

private:
    unordered_map<int, set<int>> reachable_lists_;
};

int main() {
    RouteManager routes;

    int query_count;
    cin >> query_count;

    for (int query_id = 0; query_id < query_count; ++query_id) {
        string query_type;
        cin >> query_type;
        int start, finish;
        cin >> start >> finish;
        if (query_type == "ADD"s) {
            routes.AddRoute(start, finish);
        } else if (query_type == "GO"s) {
            cout << routes.FindNearestFinish(start, finish) << "\n"s;
        }
    }
}