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

typedef long long ll;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    ll n, m, s;
    cin >> n >> m >> s;

    vector<pair<ll, ll>> intervals;
    for (ll i = 0; i < m; ++i) {
        ll l, r;
        cin >> l >> r;
        intervals.emplace_back(l, r);
    }

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

    ll idx = -1;
    for (ll i = 0; i < m; ++i) {
        if (intervals[i].first <= s && s <= intervals[i].second) {
            idx = i;
            break;
        }
    }

    vector<pair<ll, ll>> gaps;

    if (intervals[0].first > 1) {
        gaps.emplace_back(1, intervals[0].first - 1);
    }

    ll prev_r = intervals[0].second;
    for (ll i = 1; i < m; ++i) {
        ll curr_l = intervals[i].first;
        if (prev_r + 1 < curr_l) {
            gaps.emplace_back(prev_r + 1, curr_l - 1);
        }
        prev_r = intervals[i].second;
    }

    if (prev_r < n) {
        gaps.emplace_back(prev_r + 1, n);
    }

    vector<ll> candidates;

    for (auto& gap : gaps) {
        ll a = gap.first;
        ll b = gap.second;

        if (a > s) {
            candidates.push_back(a);
        } else if (b < s) {
            candidates.push_back(b);
        }
    }

    ll best_p = -1;
    ll min_dist = LLONG_MAX;

    for (ll p : candidates) {
        ll dist = abs(p - s);
        if (dist < min_dist || (dist == min_dist && p < best_p)) {
            min_dist = dist;
            best_p = p;
        }
    }

    cout << best_p << endl;

    return 0;
}