#include <cstdio>
#include <fstream>

using namespace std;

#define f first
#define s second

pair<int,int> v[100001];

int main ()
{
	int n,m,k;
	ifstream in ("stergeri.in");
	in>>n>>m>>k;
	for(int i=1;i<=m;++i)
		in>>v[i].f>>v[i].s;
	for(int i=m;i;--i)
		if(v[i].f<=k)
			k+=v[i].s-v[i].f+1;
	freopen ("stergeri.out","w",stdout);
	printf("%d",k);
	return 0;
}