J=lambda:list(map(int,input().split())) N,*_=J() P=[J()for i in range(N*2)] L=9**5 C=L*L def D(c): h=d=0 for x,y in P:v=a*x+b*y+c;h|=v==0;d+=v>0 return h,d a,b=1,-L while 1: b,l,r=b+1,-C-1,C while l+1>1;h,d=D(m) if d