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#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;

template<class T> using ordered_set =tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update> ;

#define debug(x) cout << "[" <<  #x << " " << x << "] ";

#define ar array
#define ll long long
#define ld long double
#define sz(x) ((int)x.size())
#define all(a) (a).begin(), (a).end()

typedef vector<int> vi;
typedef pair<int,int> pi;

const int MAX_N = 1e5 + 5;
const ll MOD = 1e9 + 7;
const ll INF = 1e13;
const ld EPS = 1e-9;

void solve() {
    ll n,m,s;
    cin >> n >> m >> s;
    vector<pair<ll,ll>> full(m);
    for (int i = 0; i < m; i++) {
        cin >> full[i].first >> full[i].second;
    }
    sort(all(full));
    vector<pair<ll,ll>> combined;
    combined.push_back(full[0]);
    for (int i = 1; i < m; i++) {
        if (full[i].first -1 == combined.back().second){
            combined.back().second = full[i].second;
        }
        else{
            combined.push_back(full[i]);
        }
    }

    int school = -1;
    for (int i = 0; i < sz(combined); i++) {
        if (combined[i].first <= s && s <= combined[i].second) {
            school = i;
            break;
        }
    }

    ll left = combined[school].first -1;
    ll right = combined[school].second + 1;
    if (left <1){
        left = -INF;
    }
    if (right > n){
        right = INF;
    }
    if (abs(s - left) <= abs(s-right)){
        cout << left << "\n";
    }
    else{
        cout << right << "\n";
    }

}


int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int tc = 1;
    for (int t = 1; t <= tc; t++) {
        // cout << "Case #" << t << ": ";
        solve();
    }
}