#include<fstream>

using namespace std;

#define max_m 100010

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

int i , n , m , k;

struct interval{
	int x ;
	int y ;
}V[max_m];

void read(){
	
	f>>n>>m>>k;
	
	for(i=1;i<=m;i++)
		f>>V[i].x>>V[i].y;
	
}

void solve(){
	
	for(i=m ; i>=1 ; i-- ){
		
		if(V[i].x <= k)
			k+=(V[i].y - V[i].x + 1);
		
	}
	
	g<<k;
	
}


int main(){
	
	read();
	
	solve();
	
	return 0;
}