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#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) int((x).size())
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;

#ifdef LOCAL
auto operator<<(auto& o, auto x) -> decltype(x.first, o);
auto operator<<(auto& o, auto x) -> decltype(x.end(), o) {
  o << "{";
  for (int i = 0; auto y : x) o << ", " + !i++ * 2 << y;
  return o << "}"; }
auto operator<<(auto& o, auto x) -> decltype(x.first, o) {
  return o << "(" << x.first << ", " << x.second << ")"; }
void __print(auto... x) { ((cerr << x << " "), ...) << endl; }
#define debug(x...) __print("[" #x "]:", x)
#else
#define debug(...) 2137
#endif

const int M = 1010;
ll n, s;
int m;
ll l[M], r[M];

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin >> n >> m >> s;
  rep(i, 0, m) cin >> l[i] >> r[i];
  pair<ll, ll> odp = {1e18, -1};
  ll x = s - 1;
  while (x >= 1) {
    bool f = 0;
    rep(i, 0, m) {
      if (l[i] <= x && x <= r[i]) {
        x = l[i] - 1;
        f = 1;
        break;
      }
    }
    if (!f) {
      odp = min(odp, {abs(x - s), x});
      break;
    }
  }
  x = s + 1;
  while (x <= n) {
    bool f = 0;
    rep(i, 0, m) {
      if (l[i] <= x && x <= r[i]) {
        x = r[i] + 1;
        f = 1;
        break;
      }
    }
    if (!f) {
      odp = min(odp, {abs(x - s), x});
      break;
    }
  }
  cout << odp.second << '\n';
}