#include <iostream>
#include <fstream>
using namespace std;
struct nr
{
	int a;
	int b;
};
nr mo[100001];
int main()
{
	ifstream in("stergeri.in");
	ofstream out("stergeri.out");
	int i, n, m, k;
	in >> n;
	in >> m;
	in >> k;
	for (i = 1;i <= m;i++)
	{
		in >> mo[i].a;
		in >> mo[i].b;
		n -= (mo[i].b - mo[i].a + 1);
	}
	for (i = m;i >= 1;i--)
	{
		n += (mo[i].b - mo[i].a + 1);
		if (mo[i].a <= k)
		{
			k += (mo[i].b - mo[i].a + 1);
		}
	}
	out << k;
}