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#include <bits/stdc++.h>

using namespace std;

#define _DEBUG
#ifdef _DEBUG
template<typename T1, typename T2> auto& operator<<(ostream& o, pair<T1, T2> a) { return o << "(" << a.first << ", " << a.second << ")"; }
template<typename T, typename OS> auto& operator<<(OS& o, T a) { o << "{"; for(auto b : a) o << b << ", "; return o << "}"; }
#define dbg(x...) cerr << "[" #x "]: ", [](auto... args) { ((cerr << args << ", "),...) << "\n"; }(x)
#else
#define dbg(...)
#endif

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define F first
#define S second

using ll = long long;
using ld = long double;
using pll = pair<ll,ll>;
using vi = vector<int>;

ll brute(ll n, ll s, vector<pll> vs) {
  ll ans = 1000000000000000000;
  for(ll i = 1; i <= n; i++) {
    bool ok = true;
    for(auto [l, r] : vs) {
      if(l <= i && r >= i) {
        ok = false;
        break;
      }
    }
    if(ok && std::abs(ans - s) > std::abs(i - s)) {
      ans = i;
    }
  }
  return ans;
}

ll solve(ll n, ll s, vector<pll> vs) {
  sort(all(vs));
  int b = 0;
  for(int i = 0; i < vs.size(); i++) {
    auto [l, r] = vs[i];
    if(s >= l && s <= r) {
      b = i;
      break;
    }
  }

  ll ans = 1000000000000000;

  for(int i = b - 1; i >= 0; i--) {
    auto [pl, pr] = vs[i + 1];
    auto [cl, cr] = vs[i];
    if(cr < pl - 1) {
      if(std::abs(s - (pl - 1)) < std::abs(s - ans)) {
        ans = pl - 1;
      }
    }
  }

  if(std::abs(s - (vs.front().first - 1) ) < std::abs(s - ans) && vs.front().first - 1 > 0) {
    ans = vs.front().first - 1;
  }

  for(int i = b + 1; i < vs.size(); i++) {
    auto [pl, pr] = vs[i - 1];
    auto [cl, cr] = vs[i];
    if(cl > pr + 1) {
      if(std::abs(s - (pr + 1)) < std::abs(s - ans)) {
        ans = pr + 1;
      }
    }
  }

  if(std::abs(s - (vs.back().second + 1) ) < std::abs(s - ans) && vs.back().second + 1 <= n) {
    ans = vs.back().second + 1;
  }

  return ans;
}

void test() {
  static mt19937 gen(123);
  ll n = uniform_int_distribution<ll>(2, 1000)(gen);
  ll m = uniform_int_distribution<ll>(1, 200)(gen);
  vector<pll> vs;
  for(int i = 0; i < m; i++) {
    ll l, r;
    if(i == 0) {
      l = uniform_int_distribution<ll>(1, 100)(gen);
      r = uniform_int_distribution<ll>(l, l + 100)(gen);
    }
    else {
      if(vs.back().second == n) {
        break;
      }
      l = uniform_int_distribution<ll>(vs.back().second + 1, vs.back().second + 100)(gen);
      r = uniform_int_distribution<ll>(l, l + 100)(gen);
    }
    n = max(n, r);
    vs.push_back({l, r});
  }
  m = vs.size();
  bool ok = false;
  for(ll i = 1; i <= n; i++) {
    bool covered = false;
    for(auto [l, r] : vs) {
      if(i >= l && i <= r) {
        covered = true;
        break;
      }
    }
    if(!covered) {
      ok = true;
      break;
    }
  }

  int b = uniform_int_distribution<ll>(0, m - 1)(gen);
  ll s = uniform_int_distribution<ll>(vs[b].first, vs[b].second)(gen);

  if(!ok) {
    return;
  }

  auto ans1 = solve(n, s, vs);
  auto ans2 = brute(n, s, vs);
  if(ans1 != ans2) {
    cout << "WHATA";
    assert(false);
  }
}

void solve() {
  ll n, m, s;
  cin >> n >> m >> s;
  vector<pll> vs(m);
  for(int i = 0; i < m; i++) {
    ll l, r;
    cin >> l >> r;
    vs[i] = {l, r};
  }
  cout << solve(n, s, vs);
}

int main() {
  // for(int i = 0; i < 1000000; i++) {
    // test();
  // }
  // return 0;
  //test();
  cin.tie(0)->sync_with_stdio(0);
  int t = 1;
  //cin >> t;
  while(t--) {
    solve();
    cout << "\n";
  }
  return 0;
}