import sys
input = sys.stdin.readline

def toNum(s):
	ret = 0
	for c in s:
		k = 3 - (ord(c) - ord('A'))
		ret <<= 2
		ret += k
	return ret

N, K = map(int, input().split())
st = set([toNum(input().rstrip()) for _ in [0] * N])

visited = [0] * (1 << (K << 1))
for sv in st:
	if(visited[sv] == 1):
		continue
	stk = [sv]
	while(stk):
		v = stk.pop()
		for i in range(K):
			k = i << 1
			if(((v >> k) & 3) == 0):
				continue
			nv = v - (1 << k)
			if(visited[nv] == 1):
				continue
			visited[nv] = 1
			stk.append(nv)

ans = sum(visited[k] for k in st)
print(ans)