class UnionFind:
	def __init__(self, n):
		self.n = n
		self.parents = [-1] * n
	
	def find(self, x):
		if self.parents[x] < 0:
			return x
		else:
			self.parents[x] = self.find(self.parents[x])
			return self.parents[x]
	
	def union(self, x, y):
		x = self.find(x)
		y = self.find(y)
		if x == y:
			return
		if self.parents[x] > self.parents[y]:
			x, y = y, x
		self.parents[x] += self.parents[y]
		self.parents[y] = x

n = int(input())
x = [0] * n
y = [0] * n
t = [0] * n
uf = UnionFind(n)

for i in range(n):
	x[i], y[i], t[i] = map(int,input().split())

a = []
dist = 0
for i in range(n):
	for j in range(i+1, n):
		if t[i] == t[j]:
			dist = (x[i] - x[j]) ** 2 + (y[i] - y[j]) ** 2
		else:
			p2 = x[i] ** 2 + y[i] ** 2
			q2 = x[j] ** 2 + y[j] ** 2
			p2, q2 = min(p2, q2), max(p2, q2)
			suki = 10 ** 12
			kirai = -1
			while suki - kirai > 1:
				targ = (suki + kirai) // 2
				tmp = q2 - p2 - targ
				if tmp <= 0 or tmp * tmp <= 4 * targ * p2:
					suki = targ
				else:
					kirai = targ
			dist = suki
			#print(dist)
		a.append((dist << 30) + (i << 15) + j)

a.sort()
mask = (1 << 15) - 1
ans = 0
for v in a:
	dist = v >> 30
	i = (v >> 15) & mask
	j = v & mask
	ans = dist
	#print(dist, i, j)
	uf.union(i, j)
	if uf.find(0) == uf.find(n-1):
		break

print(ans)