#include <fstream>
#include <iostream>

using namespace std;

int n, m, k, i, a[2000003], b[100100];

int main()
{
	ifstream f("stergeri.in");
	ofstream g("stergeri.out");

	f >> n >> m >> k;
	for (i = 1; i <= m; i++)
	{
		f >> a[i] >> b[i];
	}
	for (i = m; i >= 1; i--)
	{
		if (a[i] <= k)
			k += b[i] - a[i] + 1;
	}
	g << k;
	return 0;
}