#define _CRT_SECURE_NO_WARNINGS

#include <cstdio>


#define M 100352

int a[M], b[M];


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

	int n, m, k;
	scanf("%d%d%d", &n, &m, &k);

	for (int i = 0; i < m; i++)
		scanf("%d%d", &a[i], &b[i]);

	for (int i = m - 1; i >= 0; i--)
		if (a[i] <= k)
			k += b[i] - a[i] + 1;

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

	return 0;
}