#include<fstream.h>

long long n,m,k,i;
struct interval {long x,y;};
interval intv[100000];

int main()
{	ifstream fin("stergeri.in");
	ofstream fout("stergeri.out");
	fin>>n>>m>>k;
	for(i=0;i<m;i++)	fin>>intv[i].x>>intv[i].y;
	for(i=m-1;i>=0;i--)
		if(intv[i].x<=k) k+=(intv[i].y-intv[i].x)+1;
	fout<<k;
	return 0;
}