#include <cstdio>
#define DIM 100000
using namespace std;
int i,m;
long long a[DIM],n,b[DIM];
long long k;
int main()
{
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    scanf("%lld%d%lld\n",&n,&m,&k);
    for(i=1; i<=m; ++i)
       scanf("%lld%lld\n",&a[i],&b[i]);
    for(m; m>=1; --m)
         {
         if(k>a[m]) k+=b[m]-a[m]+1;
         }
   printf("%lld\n",k);
   return 0;
}