#include <cstdio>

const int MAXN = 1e5;

int a[MAXN], b[MAXN];

int main() {
  int n, m, k;
  FILE *f = fopen("stergeri.in", "r");
  fscanf(f, "%d%d%d", &n, &m, &k);
  for (int i = 0; i < m; ++i) {
    fscanf(f, "%d%d", &a[i], &b[i]);
  }
  fclose(f);
  for (int i = m - 1; i >= 0; --i) {
    if (a[i] <= k) {
      k += b[i] - a[i] + 1;
    }
  }
  f = fopen("stergeri.out", "w");
  fprintf(f, "%d\n", k);
  fclose(f);
  return 0; 
}