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#include <bits/stdc++.h>
#define MP make_pair
#define PB push_back
#define int long long
#define st first
#define nd second
#define rd third
#define FOR(i, a, b) for(int i =(a); i <=(b); ++i)
#define RE(i, n) FOR(i, 1, n)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define REP(i, n) for(int i = 0;i <(n); ++i)
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define __builtin_ctz __builtin_ctzll
#define __builtin_clz __builtin_clzll
#define __builtin_popcount __builtin_popcountll
using namespace std;
template<class T1, class T2>
ostream& operator<< (ostream &out, pair<T1, T2> pair) { return out << "(" << pair.first << ", " << pair.second << ")";}
template<class A, class B, class C> struct Triple { A first; B second; C third;
  bool operator<(const Triple& t) const { if (st != t.st) return st < t.st; if (nd != t.nd) return nd < t.nd; return rd < t.rd; } };
  template<class T> void ResizeVec(T&, vector<int>) {}
  template<class T> void ResizeVec(vector<T>& vec, vector<int> sz) {
    vec.resize(sz[0]); sz.erase(sz.begin()); if (sz.empty()) { return; }
    for (T& v : vec) { ResizeVec(v, sz); }
  }
  typedef Triple<int, int, int> TIII;
  template<class A, class B, class C>
  ostream& operator<< (ostream &out, Triple<A, B, C> t) { return out << "(" << t.st << ", " << t.nd << ", " << t.rd << ")"; }
  template<class T> ostream& operator<<(ostream& out, vector<T> vec) { out<<"("; for (auto& v: vec) out<<v<<", "; return out<<")"; }
  template<class T> ostream& operator<<(ostream& out, set<T> vec) { out<<"("; for (auto& v: vec) out<<v<<", "; return out<<")"; }
  template<class L, class R> ostream& operator<<(ostream& out, map<L, R> vec) { out<<"("; for (auto& v: vec) out<<v<<", "; return out<<")"; }
  
template<typename TH> void _dbg(const char* sdbg, TH h) { cerr<<sdbg<<"="<<h<<"\n"; }
template<typename TH, typename... TA> void _dbg(const char* sdbg, TH h, TA... t) {
  while(*sdbg != ',') { cerr<<*sdbg++; } cerr<<"="<<h<<","; _dbg(sdbg+1, t...);
}
#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (__VA_ARGS__)
#define cerr if(0)cout
#endif
typedef long double LD;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<pair<int, int> > VPII;

template<class C> void mini(C&a4, C b4){a4=min(a4, b4); }
template<class C> void maxi(C&a4, C b4){a4=max(a4, b4); }

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//mt19937 rng(57);


struct Sol {
  void Test() {
    
    
    
    
    
  }
};

int32_t main() {

  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(10);
  cerr << fixed << setprecision(10);
  cin.tie(0);
  //double beg_clock = 1.0 * clock() / CLOCKS_PER_SEC;
  
  int n, m, s;
  cin>>n>>m>>s;
  map<int, int> prv, nxt;
  prv[0] = -3 * n;
  nxt[n + 1] = 3 * n;
  int fir_lewo, fir_prawo;
  RE (i, m) {
    int a, b;
    cin>>a>>b;
    if (a <= s && s <= b) {
      fir_lewo = a - 1;
      fir_prawo = b + 1;
    }
    prv[b] = a - 1;
    nxt[a] = b + 1;
  }
  while (prv.count(fir_lewo)) {
    fir_lewo = prv[fir_lewo];
  }
  while (nxt.count(fir_prawo)) {
    fir_prawo = nxt[fir_prawo];
  }
  if (s - fir_lewo <= fir_prawo - s) {
    cout<<fir_lewo<<endl;
  } else {
    cout<<fir_prawo<<endl;
  }
    
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  return 0;
}