n = 10 ** 6

dp = [True] * (n + 1)
dp[1] = False
for i in range(2, n + 1):
	for j in range(i * i, n + 1, i):
		dp[j] = False

m = 1000
ans = [[''] * m for _ in [0] * m]
for i in range(m):
	for j in range(m):
		if(dp[i * m + j]):
			ans[i][j] = '#'
		else:
			ans[i][j] = '.'

for s in ans:
	print(''.join(s))