#include <stdio.h>

int n,m,k,x,y,s,e,p;

int main()
{
	freopen("stergeri.in","r",stdin);
	freopen("stergeri.out","w",stdout);
	int i,j;
	scanf("%d%d%d",&n,&m,&k);
	e=0;
	s=0;
	p=2000000010;
	for (i=1; i<=m; ++i) 
	{
		scanf("%d%d",&x,&y);
		if (x+e<k)
		{
			k+=(y-x+1);
			e+=(y-x+1);
			if (k>=p) k+=s;
		}
		else if (x+e>k) 
		{
			s+=y-x+1;
			if (p>x+e) p=x+e;
		}
	}
	printf("%d\n",k);
	return 0;
}