# 点と平面の距離
N =  int(input())
P = tuple(map(lambda x:float(x),input().split()))
lsXYZ = [tuple(map(lambda x:float(x),input().split())) for i in range(N)]
def point_to_plane(A,B,C):
    AB = (B[0]-A[0],B[1]-A[1],B[2]-A[2])
    AC = (C[0]-A[0],C[1]-A[1],C[2]-A[2])
    outer = (AB[1]*AC[2]-AB[2]*AC[1],AB[2]*AC[0]-AB[0]*AC[2],AB[0]*AC[1]-AB[1]*AC[0])
    return outer[0],outer[1],outer[2],-outer[0]*A[0]-outer[1]*A[1]-outer[2]*A[2]

def dist_point_plane(P,a,b,c,d):
    return abs(a*P[0]+b*P[1]+c*P[2]+d)/((a**2+b**2+c**2)**(1/2))
ans = 0
for i in range(N-2):
    for j in range(i+1,N-1):
        for k in range(j+1,N):
            a,b,c,d = point_to_plane(lsXYZ[i],lsXYZ[j],lsXYZ[k])
            ans += dist_point_plane(P,a,b,c,d)
print(ans)