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

#define PII pair <int, int>
#define st first
#define dr second
#define mp make_pair

int i, j;
int N, M, K;
int x, y;

vector <PII> Erase;
vector <PII> :: reverse_iterator it;

int main() {
	freopen("stergeri.in","r",stdin);
	freopen("stergeri.out","w",stdout);
	scanf("%i%i%i", &N, &M, &K);
	for (i = 1; i <= M; ++i)
		scanf("%i%i", &x, &y),
		Erase.push_back(mp(x, y));
	for (it = Erase.rbegin(); it != Erase.rend(); ++it) {
		if (it->st <= K)
			K += (it->dr - it->st + 1);
	}
	printf("%i\n", K);
	return 0;
}