#include<iostream>
#include<fstream>
using namespace std;

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

const int N = 100010;

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

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