#include<fstream>
using namespace std;
ifstream in("stergeri.in");
ofstream out("stergeri.out");

const int nmax = 100006;
int v1[nmax], v2[nmax], n, k, m;

int main(){
	int player_unu=0;

	in>>n>>m>>k;
	for(int i = 0; i<m; i++)
	{
		in>>v1[i]>>v2[i];
	}

	for(int i = m-1; i>=0; i--)
	{
		if(v1[i]<=k)
			k += (v2[i] - v1[i] + 1);
	}

	out<<k<<'\n';

	return player_unu;
}