#include<fstream>
#include<algorithm>
#define FIN "stergeri.in"
#define FOUT "stergeri.out"
#define NMAX 1<<31
#define MMAX 100005
#define f first
#define s second
using namespace std;
pair<int,int> itv[MMAX];
int N,M,K;
int main()
{freopen(FIN,"r",stdin);
 freopen(FOUT,"w",stdout);
 scanf("%d %d %d",&N,&M,&K);
  for(int i=0;i<M;i++)
   {scanf("%d %d",&itv[i].f,&itv[i].s);}
 for(int i=M-1;i>=0;i--)
  {if(itv[i].f<=K) K+=itv[i].s-itv[i].f+1;
         }  
  printf("%d",K);      
   return 0;}