#include <iostream>
using namespace std;

int v[100010], w[100010];

int main()
{
  freopen("stergeri.in","r",stdin);
  freopen("stergeri.out","w",stdout);
  
  int N, M, K;

  cin >> N >> M >> K;
  
  for (int i = 1; i <= M; ++i)
    cin >> v[i] >> w[i];

  for (int i = M; i >= 1; --i)
    if (v[i] <= K)        
      K += (w[i] - v[i] + 1);
  
  cout << K << "\n";
  return 0;
}