#include <stdio.h>
#define DIM 100001
struct punct {
  long int x,y;
} v[DIM];
unsigned long int n,m,k,i;

int main(){
  FILE *f = fopen("stergeri.in","r");
  fscanf(f,"%ld %ld %ld",&n,&m,&k);

  for (i=1;i<=m;i++) {
    fscanf(f,"%ld %ld",&v[i].x,&v[i].y);
  }
  fclose(f);
  for (i=m;i>=1;i--)
    if (v[i].x<=k)
      k+=(v[i].y-v[i].x+1);

  FILE *g = fopen("stergeri.out","w");
  fprintf(g,"%ld",k);
  fclose(g);
  return 0;
}