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#include <bits/stdc++.h>

using namespace std;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    vector<pair<long long, long long>> intervals;
    long long n, s, a, b;
    int m;
    cin >> n >> m >> s;
    for (int i = 0; i < m; i++) {
        cin >> a >> b;
        intervals.push_back({a, b});
    }
    sort(intervals.begin(), intervals.end());
    vector<pair<long long, long long>> new_intervals;
    new_intervals.push_back(intervals[0]);
    for (int i = 1; i < m; i++) {
        if (new_intervals.back().second + 1 == intervals[i].first) {
            new_intervals.back().second = intervals[i].second;
        } else {
            new_intervals.emplace_back(intervals[i]);
        }
    }
    for (int i = 0; i < new_intervals.size(); i++) {
        if (new_intervals[i].first <= s && new_intervals[i].second >= s) {
            if (new_intervals[i].second == n ||
                (new_intervals[i].first > 1 &&
                 s - new_intervals[i].first <= new_intervals[i].second - s))
                cout << new_intervals[i].first - 1 << '\n';
            else
                cout << new_intervals[i].second + 1 << '\n';
        }
    }
    return 0;
}