#include <iostream>
#include <fstream>
#include <vector>

std::vector<int> a, b;
int n, m, k;

int main()
{
  std::ifstream in("stergeri.in");
  in >> n >> m >> k;
  for (int i = 0; i < m; ++i) {
    int li, lf;
    in >> li >> lf;
    a.push_back(li);
    b.push_back(lf);
  }
  in.close();

  for (int i = m - 1; i >= 0; --i) {
    if (a[i] <= k) {
      k += b[i] - a[i] + 1;
    }
  }

  std::ofstream out("stergeri.out");
  out << k << std::endl;

  return 0;
}