#include <fstream>
using namespace std;

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

int x[100005], y[100005], n, m, k, i;
bool kay;

int main(){
	f>>n>>m>>k;
	for (i=1; i<=m; i++) f>>x[i]>>y[i];
	
	kay=1;
	while (kay){
		kay=0;
		for (i=1; i<=m; i++){
			if (x[i]<=k && x[i]!=0) {
				k+=(y[i]-x[i]+1);
				kay=1;
				x[i]=0; y[i]=0;
			}
		}
	}
	g<<k;
}