#include <fstream>

using namespace std;

int N, M, K;
int v[100010][2];

void Citire ()
{
	ifstream fin ("stergeri.in");
	fin >> N >> M >> K;
	for (int i = M - 1; i >= 0; i--)
	{
		fin >> v[i][0] >> v[i][1];
	}
	fin.close ();
}

void Business ()
{
	for (int i = 0; i < M; i++)
	{
		if (v[i][0] <= K) K += v[i][1] - v[i][0] + 1;
	}
}

void Scriere ()
{
	ofstream fout ("stergeri.out");
	fout << K;
	fout.close ();
}

int main ()
{
	Citire ();
	Business ();
	Scriere ();
	return 0;
}