#include <stdio.h>

int N, M, K;

#define MAXM 100005
int L[MAXM], R[MAXM];

int main()
{
	freopen("stergeri.in", "rt", stdin);
	freopen("stergeri.out", "wt", stdout);

	scanf("%d %d %d", &N, &M, &K);
	for (int i = 0; i < M; i++)
		scanf("%d %d", L + i, R + i);

	for (int i = M - 1; i >= 0; i--)
	{
		if (L[i] > K)
			continue;
		K += R[i] - L[i] + 1;
	}

	printf("%d\n", K);

	return 0;
}