root = [i for i in range(N + 1)]
size = [1] * (N + 1)
 
def find(x):
  y = root[x]
  if x == y:
    return x
  else:
    z = find(y)
    root[x] = z
    return z

def union(x, y):
  rx = find(x)
  ry = find(y)
  sx = size[rx]
  sy = size[ry]
  if rx == ry:
    return 0
  else:
    if sx >= sy:
      root[ry] = rx
      size[rx] = sx + sy
    else:
      root[rx] = ry
      size[ry] = sx + sy
    return sx * sy