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// Bartłomiej Sitnik

#include <bits/stdc++.h>

using namespace std;

int main()
{
    long long n;
    long long s;
    int m;
    long long l, r;

    cin >> n >> m >> s;

    set<pair<long long, long long>> pary;

    pary.insert({1ll, n});

    for (int i = 0; i < m; i++)
    {
        cin >> l >> r;
        auto it = pary.upper_bound({l, r});
        it--;
        if (it == pary.end())
            continue;
        if (it->first == l and it->second == r)
        {
            pary.erase(it);
            continue;
        }
        if (it->first < l and it->second > r)
        {
            pair<long long, long long> p1, p2;
            p1 = {it->first, l-1};
            p2 = {r+1, it->second};
            pary.erase(it);
            pary.insert(p1);
            pary.insert(p2);
            continue;
        }
        if (it->first <= l and it->second > r)
        {
            pair<long long, long long> p2;
            p2 = {r+1, it->second};
            pary.erase(it);
            pary.insert(p2);
            continue;
        }
        if (it->first < l and it->second >= r)
        {
            pair<long long, long long> p1;
            p1 = {it->first, l-1};
            pary.erase(it);
            pary.insert(p1);
            continue;
        }
        if (it->first <= l and it->second < r)
        {
            if (it->first < l)
                pary.insert({it->first, l-1});
            
            while (it != pary.end() and it->second <= r)
            {
                auto it2 = it;
                it++;
                pary.erase(it2);
            }
            
            if (it->second > r and it->first <= r)
            {
                pary.insert({r+1, it->second});
                pary.erase(it);
            }
            continue;
        }
    }


    auto it = pary.lower_bound({s, s});
    it--;
    auto it2 = pary.lower_bound({s, s});
    if (it2 != pary.end() and s - it->second > it2->first - s)
        cout << it2->first;
    else
        cout << it->second;

    return 0;
}