#include<fstream>
#include<vector>
using namespace std;

int n, m , k;
vector< pair<int, int> > a;

int main()
{
	ifstream fin("stergeri.in");
	ofstream fout("stergeri.out");
	
	fin >> n >> m >> k;
	a.resize(m + 1);
	
	for(int i = 1; i <= m; ++i)
		fin >> a[i].first >> a[i].second;
	
	for(int i = m; i >= 1; --i)
		if( a[i].first <= k)
			k += a[i].second - a[i].first + 1;
		
	fout << k;
	
	fin.close();
	fout.close();
	return 0;
}