#include<stdio.h>
int x[100005],y[100005];
int main()
{
	freopen("stergeri.in","r",stdin);
	freopen("stergeri.out","w",stdout);
	int n,m,k,i;
	scanf("%d%d%d",&n,&m,&k);
	for(i=1;i<=m;i++)
		scanf("%d%d",&x[i],&y[i]);
	for(i=m;i>0;i--)
		if(x[i]<=k)
			k=k+y[i]-x[i]+1;
	printf("%d\n",k);
	return 0;
}