STOP sign (book)

n = int(input())
dots = n + 1
underscores = 2 * n + 1
print("{0}{1}{0}".format("." * dots, "_" * underscores))
underscores -= 2
dots -= 1

for i in range(n):
  print("{0}//{1}\\\\{0}".format("." * dots, "_" * underscores))
  underscores += 2
  dots -= 1

print("//{0}STOP!{0}\\\\".format("_" * round((underscores - 5) / 2)))

for i in range(n):
  print("{0}\\\\{1}//{0}".format("." * i, "_" * underscores))
  underscores -= 2