a[900];		b;c;d=1		;e=1;f;		g;h;O;		main(k,l)char*		*l;{g=		atoi(*		++l);		for(k=0;k*k<		g;b=k		++>>1)		;for(h=		0;h*h<=g;++h);		--h;c=(		(h+=g>h		*(h+1))		-1)>>1;while(d		<=g){		++O;for		(f=0;f<		O&&d<=g;++f)a[		b<<5|c]		=d++,b+=	e;for(		f=0;f<O&&d<=g;		++f)a[b		<<5|c]=		d++,c+=		e;e= -e;}for(c		=0;c<h;		++c){		for(b=0		;b<k;++b){if(b		<k/2)a[		b<<5|c]		^=a[(k		-(b+1))<<5|c]^=	a[b<<5		|c]^=a[		(k-(b+1		))<<5|c];printf(	a[b<<5|c	]?"%-4d"	:"    "		,a[b<<5|c]);}		putchar(	'\n');}}	/*Mike		Laman*/