import sys
input = sys.stdin.readline

N, K = map(int, input().split())
st = set([input()[:-1] for _ in [0] * N])

visited = set([])
for v_start in st:
    if(v_start in visited):
        continue
    stk = [v_start]
    while(stk):
        v_now = stk.pop()
        for i in range(K):
            if(v_now[i] == '0'):
                continue
            v_next = ''.join([v_now[:i], chr(ord(v_now[i]) - 1), v_now[i+1:]])
            if(v_next in visited):
                continue
            visited.add(v_next)
            stk.append(v_next)

ans = len(visited & st)
print(ans)