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

#define a first
#define b second

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

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