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#include <algorithm>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;
int main() {
  long long n, m, s;
  long long l, r;
  cin >> n >> m >> s;
  vector<pair<long long, long long>> tab(m);
  for (int i = 0; i < m; ++i) {
    cin >> tab[i].first >> tab[i].second;
  }
  sort(tab.begin(), tab.end());
  for (int i = 0; i < m; ++i) {
    if (tab[i].first <= s && s <= tab[i].second) {
      l = tab.front().first - 1;
      r = tab.back().second + 1;
      for (int j = i - 1; j >= 0; --j) {
        if (tab[j].second + 1 != tab[j + 1].first) {
          l = tab[j + 1].first - 1;
          break;
        }
      }
      for (int j = i + 1; j < m; ++j) {
        if (tab[j].first - 1 != tab[j - 1].second) {
          r = tab[j - 1].second + 1;
          break;
        }
      }
      if ((s - l <= r - s && l > 0) || r > n) {
        cout << l;
        return 0;
      } else {
        cout << r;
        return 0;
      }
    }
  }
}