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#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T> void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T> void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 1010;

ll n, s, ans = 1e18;
pll a[maxn], b[maxn];
int m, tot;

void check(ll x) {
  if (llabs(x - s) < llabs(ans - s)) ans = x;
  else if (llabs(x - s) == llabs(ans - s) && x < ans) ans = x;
}

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  cin >> n >> m >> s;
  rep (i, 1, m) cin >> a[i].fi >> a[i].se;
  sort(a + 1, a + m + 1);
  if (a[1].fi > 1) b[++tot] = pll(1, a[1].fi - 1);
  rep (i, 2, m) if (a[i].fi > a[i - 1].se + 1) b[++tot] = pll(a[i - 1].se + 1, a[i].fi - 1);
  if (a[m].se < n) b[++tot] = pll(a[m].se + 1, n);
  rep (i, 1, tot) check(b[i].fi), check(b[i].se);
  cout << ans << '\n';
}