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#include <iostream>
#include <vector>
#include <algorithm> 

using namespace std;

int main()
{
    long n;
    int m;
    long s;
    cin >> n >> m >> s;

    vector<pair<long,long>> busy;

    for (int i = 0; i < m; i++)
    {
        long l;
        long r;
        cin >> l >> r;
        busy.push_back({ l,r });
    }

    // Sortowanie po pierwszej wartości
    sort(busy.begin(), busy.end());

    // Szukamy indeksu ze szkołą
	int pos = 0;
	bool found = false;
	while (pos < m && !found)
	{
        if (busy[pos].first <= s && s <= busy[pos].second)
            found = true;
        else
            pos++;
    }

    long wynik = 1;
    long droga = n;

    // Szukamy w lewo
    long f = busy[pos].first - 1;
    int left = pos-1;
    found = false;
    while (left >= 0 && !found) {
        if (busy[left].second == f) {
            f = busy[left].first - 1;
            left--;
        }
        else
            found = true;
    }
    if (f >= 2) {
        wynik = f;
        droga = s - f;
    }
    // Szukamy w prawo
    long l = busy[pos].second + 1;
    int right = pos + 1;
    found = false;
    while (right < m && !found && l - s < droga) {
        if (busy[right].first == l) {
            l = busy[right].second + 1;
            right++;
        }
        else
            found = true;
    }
    if (l <= n && l-s < droga) {
        wynik = l;
    }

    cout << wynik << endl;

}