#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();
#define RD(v) int v=0;{int _t;while(_t=*rp++-48,_t>=0)v=v*10+_t;}

int x[1000],y[1000];
long d[1000];
int q[1000],qr,qw;

inline long sq2(long x,long y){
	return x*x+y*y;
}

main(){
	char*rp=mmap(0l,1l<<20,1,2,0,0ll);
	RD(n);
	for(int i=0;i<n;++i){
		RD(tx); x[i]=tx;
		RD(ty); y[i]=ty;
		d[i]=1l<<62;
		q[i]=i;
	}
	d[0]=0;
	qr=n;
	int i=0;
	while(i!=n-1){
		int ni;
		long nd=1l<<62;
		for(int qj=0;qj<qr;++qj){
			int j=q[qj];
			if(j!=i){
				q[qw++]=j;
				long xx=x[j]-x[i];
				long yy=y[j]-y[i];
				long t=xx*xx+yy*yy;
				if(t<d[i]) t=d[i];
				if(d[j]>t) d[j]=t;
				if(nd>d[j]) nd=d[j],ni=j;
			}
		}
		qr=qw;
		qw=0;
		i=ni;
	}
	long dn=d[n-1];
	int z=(1<<28)-1;
	for(int k=1<<28;k>>=1;){
		int nz=z^k;
		if(100l*nz*nz>=dn){
			z=nz;
		}
	}
	char wbuf[16],*wp=wbuf+16;
	*--wp=48;
	while(*--wp=z%10+48,z/=10);
	write(1,wp,wbuf+16-wp);
	_exit(0);
}