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

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

int n,m,k, a[100005], b[100005];
int main()
{
	f>>n>>m>>k;
	int i;
	
	for(i=1; i<=m; i++)
		f>>a[i]>>b[i];
	for(i=m; i; i--)
		if(a[i]<=k)
			k=k+b[i]-a[i]+1;
	g<<k;
}