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#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    long long n, s;
    int m;
    cin >> n >> m >> s;
    vector<pair<long long, long long>> intervals(m);

    for (int i = 0; i < m; i++) {
        cin >> intervals[i].first >> intervals[i].second;
    }

    sort(intervals.begin(), intervals.end());

    long long before = -1;
    long long last = -1;

    for (long long i = 0; i < m; i++) {
        long long candidate = intervals[i].first - 1;
        // cout << "[" << intervals[i].first << "," << intervals[i].second << "] candidate = " << candidate << " last=" << last << " before=" << before << "\n";
        if (candidate >= s) {
            if (last < s - 1) {
                before = s - 1;
            }
            break;
        }
        if (candidate > last) {
            before = candidate;
        }
        last = intervals[i].second;
    }
    long long after = n + 1;
    last = n + 1;
    for (long long i = m - 1; i >= 0; i--) {
        long long candidate = intervals[i].second + 1;
        // cout << "[" << intervals[i].first << "," << intervals[i].second << "] candidate = " << candidate << " last=" << last << " after=" << after << "\n";
        if (candidate <= s) {
            if (last > s + 1) {
                after = s + 1;
            }
            break;
        }
        if (candidate < last) {
            after = candidate;
        }
        last = intervals[i].first;
    }
    // cout << "after=" << after << " before=" << before << " s=" << s << "\n";

    if (before < 1) {
        cout << after;
    } else if (after > n) {
        cout << before;
    } else if (s - before <= after - s) {
        cout << before;
    } else {
        cout << after;
    }
    // cout << "\n";
}