#include <stdio.h>

int n, m, k;

typedef struct
{
	int a, b;
} interv;
interv v[100001];

int main()
{
	freopen("stergeri.in","r",stdin);
	freopen("stergeri.out","w",stdout);

	int i;
	scanf("%d %d %d", &n, &m, &k);
	for (i = 1; i <= m; i++)	scanf("%d %d", &v[i].a, &v[i].b);

	for (i = m; i >= 1; i--)
		if (k >= v[i].a) k += (v[i].b - v[i].a + 1);
	
	printf("%d\n",k);

	return 0;
}