files = [i.rstrip() for i in open("input").readlines()]

def naughtyornice(string):
    last = None
    lastlast = None

    c1 = False
    c2 = False
    for i in string:
        if i == lastlast:
            c2 = True
        lastlast = last
        last = i

    collections = []
    for i in range(len(string)):
        try:
            collections.append((string[i], string[i + 1], i))
        except IndexError:
            pass

    res = []
    for i in collections:
        for j in collections:
            if not i == j and i[0] == j[0] and i[1] == j[1] and i[2] != j[2] + 1 and j[2] != i[2] + 1:
                res.append("".join([i[0], i[1]]))

    res = set(res)

    if len(res) > 0:
        c1 = True

    print(res)

    return c1 and c2

nicecount = 0
for i in files:
    if naughtyornice(i):
        nicecount += 1

print(nicecount)