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#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int main() {
    cin.tie(0)->sync_with_stdio(0);

    ll n, m, s;
    cin >> n >> m >> s;
    vector<pair<ll, ll>> input;
    for(int i = 1; i <= m; i++) {
        ll l, r;
        cin >> l >> r;
        input.push_back({l, r});
    }

    sort(input.begin(), input.end());

    vector<pair<ll, ll>> inter;
    inter.push_back(input[0]);
    for(int i = 1; i < m; i++) {
        if(inter.back().second + 1 == input[i].first) inter.back().second = input[i].second;
        else inter.push_back(input[i]);
    }

    ll p = s;
    for(auto [l, r] : inter) {
        if(l <= s && s <= r) {
            if(l == 1) p = r + 1;
            else if(r == n) p = l - 1;
            else {
                if(s - l <= r - s) p = l - 1;
                else p = r + 1;
            }
            break;
        }
    }

    cout << p << '\n';
}