#include <cstdio>
#define DIM 100050
using namespace std;
long long a[DIM],n,i,m,b[DIM];
long long k;
int main()
{
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    scanf("%lld%lld%lld\n",&n,&m,&k);
    for( i=1; i<=m; ++i)
       scanf("%lld%lld\n",&a[i],&b[i]);
    for( i=m; i>=1; --i)
         if(k>a[i]) k+=b[i]-a[i]+1;
         
   printf("%lld\n",k);
   return 0;
}