#include<cstdio>
using namespace std;
const int nmax = 100005;
int i,n,m,k,a[nmax],b[nmax];
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",&a[i],&b[i]);
	for(i=m;i;i--) if(k>=a[i]) k+=b[i]-a[i]+1;
	printf("%d\n",k);
	return 0;
}