#include<stdio.h>
FILE*fin,*fout;
int i,j,n,m,k,t;
struct inter{
int x,y;


}a[100001];
int main(){
  fin=fopen("stergeri.in","r");
  fout=fopen("stergeri.out","w");
  fscanf(fin,"%d %d %d",&n,&m,&k);
  for(i=1;i<=m;i++){
  fscanf(fin,"%d %d",&a[i].x,&a[i].y);

  }            j=k;
  for(i=m;i>=1;i--){
     if(a[i].x<j){j=j+a[i].y-a[i].x+1;}


  }

  fprintf(fout,"%d",j);
return 0;
}