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// #pragma GCC optimize("O3")
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,bmi,bmi2,lzcnt,abm,mmx,avx,avx2,tune=native")

#include <bits/stdc++.h>

using namespace std;

// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;

// template <typename T>
// using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define rep(i, j) for (int i = 0; i < ((int)(j)); i++)
#define pb push_back
#define pf push_front
#define st first
#define nd second
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define get_unique(x) x.erase(unique(all(x)), x.end());

void TEST([[maybe_unused]] int testcase_i) {
  ll n, m, s;
  cin >> n >> m >> s;
  vector<pair<ll, ll>> v;
  rep(i, m) {
    ll a, b;
    cin >> a >> b;
    v.emplace_back(a, b);
  }
  v.emplace_back(0, 0);
  v.emplace_back(n + 1, n + 1);
  sort(all(v));
  ll cur = -1e15;
  pair<ll, ll> ans = {1e15, 1e15};
  bool occupied = false;
  for (auto [l, r] : v) {
    if (l - 1 != cur and l - 1 >= 1) {
      ans = min(ans, {abs(s - (cur + 1)), cur + 1});
      ans = min(ans, {abs(s - (l - 1)), l - 1});
    }
    if (l <= s and s <= r) {
      occupied = true;
    }
    cur = r;
  }

  if (!occupied) {
    cout << s;
  } else {
    cout << ans.second;
  }
}

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

  // cout << setprecision(20) << fixed;

  // srand(time(NULL));

  // freopen("sorting.in", "r", stdin);
  // freopen("sorting.out", "w", stdout);

  int t = 1;
  // cin >> t;
  rep(i, t) {
    TEST(i);
  }

  return 0;
}