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

using namespace std;

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);
    long long n, m, s;
    vector<pair<long long, long long>> segments;
    cin >> n >> m >> s;
    segments.resize(m);

    for (long long i = 0; i < m; ++i) {
        cin >> segments[i].first >> segments[i].second;
    }
    ranges::sort(segments);
    long long i = 0;
    while (segments[i].second < s) {
        ++i;
    }
    long long upper = i;
    while (upper < size(segments) - 1 && segments[upper + 1].first == segments[upper].second + 1) ++upper;
    long long upperBound = segments[upper].second + 1;

    long long lower = i;
    while (lower > 0 && segments[lower - 1].second + 1 == segments[lower].first) --lower;
    long long lowerBound = segments[lower].first - 1;

    long long res;
    if (upperBound > n) {
        res = lowerBound;
    } else if (lowerBound < 1) {
        res = upperBound;
    } else if (s - lowerBound <= upperBound - s) {
        res = lowerBound;
    } else {
        res = upperBound;
    }

    cout << res;
}