void main()
{double l[2000],d;int n,b,i,j;float q[50],w[50];
scanf("%d",&n);
for(i=1;i<=n;i++)
{
scanf("%f%f",&q[i],&w[i]);
}
b=1;
for(i=1;i<=n;i++)
for(j=1;j<=n;j++)
{l[b]=(double)((q[i]-q[j])*(q[i]-q[j])+(w[i]-w[j])*(w[i]-w[j]));b=b+1;}
d=l[1];
for(j=1;j<b;j++)
{if(d<=l[j])
d=l[j];}

printf("%.4f\n",(float)(sqrt(d)));
}