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