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

int main(){
	int n,m,k;
	ifstream in("stergeri.in");
	ofstream out("stergeri.out");

	in>>n>>m>>k;
	vector<int> unde;
	vector<int> cate;
	
	for(int i=0;i<m;i++){
		int x,y;
		in>>x>>y;
		unde.push_back(x);
		cate.push_back(y-x+1);
	}
	
	for(int i=unde.size()-1;i>=0;i--){
		if(unde[i]<=k){
			k+=cate[i];
		}
	}
	out<<k;
}