#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
#define mp make_pair
#define CHECK(x) if(!(x)) return false;
#define CHECKRET(x, y) if(!(x)) return (y);
#define SKIP(x) if((x)) continue;
typedef pair<int, int> pii;

#ifdef INFOARENA
#define ProblemName "stergeri"
#endif

#define MCONCAT(A, B) A B
#ifdef ProblemName
#define InFile MCONCAT(ProblemName, ".in")
#define OuFile MCONCAT(ProblemName, ".out")
#else
#define InFile "fis.in"
#define OuFile "fis.out"
#endif

int main() {
  assert(freopen(InFile, "r", stdin));
  assert(freopen(OuFile, "w", stdout));
  int N, M, K;
  scanf("%d%d%d", &N, &M, &K);
  stack<pii> S;
  while (M--) {
    int x, y;
    scanf("%d%d", &x, &y);
    S.push(mp(x, y));
  }
  while (!S.empty()) {
    int l = S.top().first;
    int r = S.top().second;
    S.pop();
    SKIP(l > K);
    K += r - l + 1;
  }
  printf("%d\n", K);
  return 0;
}