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#include <bits/stdc++.h>

using namespace std;

typedef long long ll;


int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

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

    pair<ll, ll> intervals[m + 1];
    for (int i = 1; i <= m; i++) {
        cin >> intervals[i].first >> intervals[i].second;
    }

    sort(intervals + 1, intervals + m + 1);
    int school_interval;
    for (int i = 1; i <= m; i++) {
        if (intervals[i].first <= s && s <= intervals[i].second) {
            school_interval = i;
        }
    }

    int right_interval = school_interval;
    ll right_canditate;
    while (intervals[right_interval].second + 1 == intervals[right_interval + 1].first && right_interval < m) {
        right_interval++;
    }
    right_canditate = intervals[right_interval].second + 1;

    int left_interval = school_interval;
    ll left_canditate;
    while (intervals[left_interval].first - 1 == intervals[left_interval - 1].second && left_interval > 1) {
        left_interval--;
    }
    left_canditate = intervals[left_interval].first - 1;

    ll res;

    if ((right_canditate <= n && abs(right_canditate - s) < abs(left_canditate - s)) || left_canditate == 0) {
        res = right_canditate;
    }
    else {
        res = left_canditate;
    }

    cout << res << "\n";

    return 0;
}