#include<fstream>
using namespace std;
int n,m,k;
struct Mutare{int st,dr;};
Mutare V[100010];

void Citire()
{
	int i;
	ifstream fin("stergeri.in");
	fin>>n>>m>>k;
	for(i=1;i<=m;i++)
		fin>>V[i].st>>V[i].dr;
	fin.close();
}

void Rezolvare()
{
	int i;
	for(i=m;i>0;i--)
		if(k>=V[i].st)
			k+=V[i].dr-V[i].st+1;
}

void Afisare()
{
	ofstream fout("stergeri.out");
	fout<<k<<"\n";
	fout.close();
}

int main()
{
	Citire();
	Rezolvare();
	Afisare();
	return 0;
}