#include<stdio.h>
#define Nmax 100001


int n,m,i,k,x;

struct {int li, lf;} capat[100001];

int main()
{

 freopen ("stergeri.in","r",stdin);
 freopen ("stergeri.out","w",stdout);
 scanf("%d %d %d",&n,&m,&k);
 for(i=1;i<=m;i++)
  scanf("%d %d",&capat[i].li,&capat[i].lf);
  
 x=k;
 for(i=m;i>=1;i--)
   if(x>=capat[i].li) x+=capat[i].lf-capat[i].li+1;
    
 printf("%d",x);
 
 return 0;
 }