n = int(input())
count = 0

for i in range(n):
    word = input().strip()
    seen = set()
    ans = ''

    grop = 1
    for ch in word:
        if ch != ans:
            if ch in seen:
                grop = 0
            seen.add(ch)
        ans = ch

    if grop == 1:
        count += 1

print(count)