#include<stdio.h>
FILE*fin=fopen("stergeri.in","r");
FILE*fout=fopen("stergeri.out","w");
struct intervals{int st,dr;};
intervals q[100005];
int n,m,k;
int main()
{
  int ans,i;
  fscanf(fin,"%d%d%d",&n,&m,&k);
  for(i=1;i<=m;i++)
    fscanf(fin,"%d%d",&q[i].st,&q[i].dr);
  ans=k;
  for(i=m;i>=1;i--)
    if(q[i].st<=ans) ans+=(q[i].dr-q[i].st+1); 
  fprintf(fout,"%d",ans);   
  fclose(fin);
  fclose(fout);
  return 0;  
}