#include <bits/stdc++.h>

using namespace std;

ifstream in("stergeri.in");
ofstream out("stergeri.out");

int n, m, k, x[100100], y[100100];

int main() {
	in >> n >> m >> k;
	for (int i = 1; i <= m; i++)
		in >> x[i] >> y[i];
	for (int i = m; i; i--) 
		if (x[i] <= k)
			k += (y[i] - x[i] + 1);
	out << k;
	return 0;
}