#include <fstream>
#include <algorithm>
#include <vector>

using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

int n, m, k;
vector < pair < int, int > > vec;

int main()
{
    fin >> n >> m >> k;
    for (int i = 0; i < m; ++ i)
        {
         int x, y;
         fin >> x >> y;
         vec.push_back(make_pair(x, y));
        }
    fin.close();
    for (vector < pair < int, int > > :: reverse_iterator it = vec.rbegin(); it != vec.rend(); ++ it)
        if (k >= (*it).first)
            k += (*it).second - (*it).first + 1;
    fout << k << "\n";
    fout.close();
    return 0;
}