#include<stdio.h>
#define dim 100001
using namespace std;
long long a[dim],b[dim];
int main()
{long long n,k;
int m,i;
 FILE *f=fopen("stergeri.in","r"), *g=fopen("stergeri.out","w");
 
 fscanf(f,"%lld%d%lld",&n,&m,&k);
   for(i=1;i<=m;i++)
	fscanf(f,"%lld%lld",&a[i],&b[i]);

  for(i=m;i>=1;i--)
   if(a[i]<k) k+=b[i]-a[i]+1;

fprintf(g,"%lld\n",k);
fclose(f);
fclose(g);
return 0;
}