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

#define rep(i, b, e) for(int i = (b); i <= (e); i++)
#define per(i, b, e) for(int i = (e); i >= (b); i--)
#define FOR(i, b, e) rep(i, b, (e) - 1)
#define SZ(x) int(x.size())
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
#define st first
#define nd second
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;

auto &operator<<(auto &o, pair<auto, auto> p) {
    return o << "(" << p.st << ", " << p.nd << ")"; }
auto operator<<(auto &o, auto x)->decltype(end(x), o) {
    o << "{"; int i=0; for(auto e: x) o << ", " + 2*!i++ << e;
    return o << "}"; }
#ifdef LOCAL
#define deb(x...) cerr << "[" #x "]: ", [](auto...$) { \
    ((cerr << $ << "; "),...) << endl; }(x)
#else
#define deb(...)
#endif

void solve() {
    ll n, s; int m;
    cin >> n >> m >> s;
    vector<pair<ll, ll>> ranges(m);
    for(auto &[l, r]: ranges) cin >> l >> r;
    auto check = [&](ll x) {
        auto outside = [](ll xx, ll l, ll r) {
            return xx < l || r < xx;
        };
        if(outside(x, 1, n)) return 0;
        for(auto &[l, r]: ranges) if(!outside(x, l, r)) return 0;
        return 1;
    };
    pair<ll, ll> ans = {n, 0};
    for(auto &[l, r]: ranges) for(auto cand: {l - 1, r + 1}) {
        if(check(cand)) ans = min(ans, {abs(cand - s), cand});
    }
    cout << ans.nd << '\n';
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int tt = 1;
    // cin >> tt;
    FOR(te, 0, tt) solve();
    return 0;
}