#include <bits/stdc++.h>

using namespace std;

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

const int DIM = 100005;

int x[DIM], y[DIM];

int main() {
  int n, m, k;

  fin >> n >> m >> k;
  for ( int i = 1; i <= m; ++i ) {
	fin >> x[i] >> y[i];
  }
  for ( int i = m; i >= 1; --i ) {
	if ( k >= x[i] ) {
	  k += y[i] - x[i] + 1;
	}
  }
  fout << k;
  fin.close();
  fout.close();
  return 0;
}