import re

#2-5 m: mfvxmmm
regex = re.compile(r'(\d+)-(\d+) (\w): (\w+)', re.I)
items = (re.match(regex, x).groups() for x in open("input.txt"))
items = map(lambda x: [int(x[0]), int(x[1]), *x[2:]], items)


def in_range(lower, upper, char, string):
    return (string[lower-1] == char) != (string[upper-1] == char)


count = sum(1 for x in items if in_range(*x))
print(count)