#include <cstdio>

int s,n,m,k,x[1<<17],y[1<<17];


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