#include<stdio.h>
long n,m,k,a[100007],b[100007],i;
int main()
{
	freopen("stergeri.out","w",stdout);
	freopen("stergeri.in","r",stdin);
	scanf("%ld %ld %ld",&n,&m,&k);
	for (i=1;i<=m;i++)
		scanf("%ld%ld",&a[i],&b[i]);
	for (i=m;i>=1;i--)
		if (k>=a[i])
			k+=(b[i]-a[i]+1);
	printf("%ld",k);
}