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#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,abm,mmx,tune=native")
//#pragma clang diagnostic ignored "-Wunused-const-variable"
#include<vector>
#include<iostream>
#include<stack>
#include<cmath>
#include<algorithm>
#include<set>
#include<map>
#include<string>
#include<tuple>
#include<bitset>
#include<queue>
#include<unordered_map>
#include<unordered_set>
#include<random>
#include<assert.h>
#include<ctime>
#include <cassert>
#include <thread>
#include <mutex>
#include <semaphore>
#include <chrono>
//#define int long long
#define all(a) a.begin(), a.end()
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
using namespace std;
ll gcd(ll i, ll j) {
	if (i < j)swap(i, j);
	if (j == 0)return i;
	else return gcd(j, i % j);
}
#ifdef _MY
ll __builtin_popcount(ll x) { return x ? (__builtin_popcount(x >> 1) + (x & 1)) : 0; }
#endif
template<typename T> inline T getint() {
	T val = 0;
	char c;

	bool neg = false;
	while ((c = getchar()) && !(c >= '0' && c <= '9')) {
		neg |= c == '-';
	}

	do {
		val = (val * 10) + c - '0';
	} while ((c = getchar()) && (c >= '0' && c <= '9'));

	return val * (neg ? -1 : 1);
}
const ll INF = 1e7 + 100;
const int mod = 998244353, mod1 = 1000000007;
const ld eps = 1e-7, pi = acos(-1);
const int maxT = 503, maxN = 1 << 22, A = 311;
ll bp(ll et, ll b) {
	ll res = 1;
	for (int i = 30; i >= 0; --i) {
		res = (res * res) % mod;
		if ((b & (1 << i)) != 0)res = (res * et) % mod;
	}
	return res;
}
mt19937 mt_rand(time(0));
void panic() {
	cout << "No\n";
	exit(0);
}
ld get_time() {
	ll tmr = clock();
	return (ld)tmr / CLOCKS_PER_SEC;
}
int pl(int a, int b) {
	a += b;
	if (a >= mod)
		a -= mod;
	return a;
}
int mul(ll a, ll b) {
	return a * b % mod;
}
struct base {
	double x, y;
	base(double X = 0, double Y = 0) {
		x = X;
		y = Y;
	}
};
base operator +(const base& a, const base& b) {
	return base(a.x + b.x, a.y + b.y);
}
base operator *(const base& a, const base& b) {
	return base(a.x * b.x - a.y * b.y, a.y * b.x + a.x * b.y);
}
base operator -(const base& a, const base& b) {
	return base(a.x - b.x, a.y - b.y);
}
base operator /(const base& a, const double& b) {
	return base(a.x / b, a.y / b);
}
void fft(vector<base>& a, bool invert) {
	int n = (int)a.size();

	for (int i = 1, j = 0; i < n; ++i) {
		int bit = n >> 1;
		for (; j >= bit; bit >>= 1)
			j -= bit;
		j += bit;
		if (i < j)
			swap(a[i], a[j]);
	}

	for (int len = 2; len <= n; len <<= 1) {
		double ang = 2 * pi / len * (invert ? -1 : 1);
		base wlen(cos(ang), sin(ang));
		for (int i = 0; i < n; i += len) {
			base w(1);
			for (int j = 0; j < len / 2; ++j) {
				base u = a[i + j], v = a[i + j + len / 2] * w;
				a[i + j] = u + v;
				a[i + j + len / 2] = u - v;
				w = w * wlen;
			}
		}
	}
	if (invert)
		for (int i = 0; i < n; ++i)
			a[i] = a[i] / n;
}
vector<double>mult(const vector<double>& a, const vector<double>& b, int mx_size = 1000'000) {
	int sz = 1;
	while (sz < 2 * max(a.size(), b.size()))sz <<= 1;
	vector<base>fa(sz);
	for (int i = 0; i < a.size(); ++i) {
		fa[i].x = a[i];
	}
	for (int i = 0; i < b.size(); ++i) {
		fa[i].y = b[i];
	}
	fft(fa, false);
	for (size_t i = 0; i < sz; ++i)
		fa[i] = fa[i] * fa[i] / 2;
	fft(fa, true);
	sz = min(sz, mx_size);
	vector<double>res(sz);
	for (int i = 0; i < sz; ++i) {
		res[i] = fa[i].y;
	}
	return res;
}
vector<vector<double>>vecs;
vector<double>recur(int l, int r, int max_err) {
	if (l + 1 == r) {
		return vecs[l];
	}
	int md = (r + l) / 2;
	const auto& v1 = recur(l, md, max_err);
	const auto& v2 = recur(md, r, max_err);
	return mult(v1, v2, max_err + 1);
}
unordered_map<int, ld>mp;
ld calc(int l, int r, int max_err) {
	if (mp.count(r)) {
		return mp[r];
	}
	ld res = 0;
	const auto& ers = recur(l, r, max_err);
	for (int i = 0; i < min(max_err + 1, (int)ers.size()); ++i) {
		res += ers[i];
	}
	return mp[r] = res;
}

void solve() {
	ll n, m, s;
	cin >> n >> m >> s;
	vector<ll>candidates;
	candidates.push_back(s - 1);
	candidates.push_back(s + 1);
	vector<pair<ll, ll>>segs;
	for (int i = 0; i < m; ++i) {
		ll l, r;
		cin >> l >> r;
		segs.push_back({ l, r });
		candidates.push_back(l - 1);
		candidates.push_back(r + 1);
	}
	pair<ll, ll> ans = { n + 1,n + 1 };
	for (auto x : candidates) {
		if (x<1 || x>n) {
			continue;
		}
		bool is_good = true;
		for (auto ss : segs) {
			if (ss.first <= x && x <= ss.second) {
				is_good = false;
				break;
			}
		}
		if (is_good && s != x) {
			ans = min(ans, { abs(s - x),x });
		}
	}
	cout << ans.second << "\n";
}
int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cout.precision(14);
#ifdef _MY
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);


	/*time_t start, end;
	time(&start);*/
#else
	//freopen("epic.in", "r", stdin); freopen("epic.out", "w", stdout);
#endif
   // init();
	int t = 1;
	//cin >> t;
	while (t--) {
		solve();
	}
#ifdef _MY
	cout << "Time taken is : " << fixed << get_time() << " sec " << "\n";
#endif
	return 0;
}