#include <iostream.h>
#include <fstream.h>
struct stiva{long inc,sf; stiva *prec; };
int main()
{
	stiva *varf,*nou;
	fstream f("stergeri.in",ios::in), g("stergeri.out",ios::out);
	long i,n,m,k;
	f>>n>>m>>k;
	varf=NULL;

	for(i=1;i<=m;i++)
	{
		nou=new stiva;
		f>>nou->inc>>nou->sf;
		nou->prec=varf;
		varf=nou;
	}
	long inc,sf;
	while(varf!=NULL)
	{
		inc=varf->inc;
		sf=varf->sf;
		nou=varf;
		varf=varf->prec;
		delete nou;
		if(k>=inc)
			k+=sf-inc+1;
	}
	g<<k;
	g.close();
	f.close();
	return 0;
}