eval'K,X,Y='+`dd`.split*?,
l=1
x,y,*s=X.abs,Y.abs
d=x+y
x,y=y,x if f=x<y
K%2-d%2<0&&p(-1)+exit
d!=K&&(l+=[~-d/K,1].max
l+=1&d-K*l
v=K>(t=K*l-d>>1)?0:t-t=K
a=K-t
2.upto(l){s<<(u=f ?-t:a)<<a-t-u
a+=q=[x+v-a,K].min
t-=K-q})
puts l,s.map{|a|X,Y=Y,X
a*=Y<=>0.1},X,Y