#include <fstream>
using namespace std;

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

const int Dim = 100001;
int n,m,k;
pair < int , int > M[Dim];

int main() {
	
	fin >> n >> m >> k;
	for ( int i = 1; i <= m; ++i)
		fin >> M[i].first >> M[i].second;
	for ( int i = m; i >= 1; --i) { 
		if ( M[i].first<= k)
			k += M[i].second - M[i].first + 1;
	}
	fout << k;
}