"""
Solution to 2020/01
"""

COUNT = 0
with open('input', 'r') as file:
    for line in file.readlines():
        rule, char, password = line.strip().split()
        char = char[0]
        pos_1, pos_2 = rule.split('-')
        pos_1 = int(pos_1) - 1
        pos_2 = int(pos_2) - 1

        is_valid = (password[pos_1] == char) ^ (password[pos_2] == char)

        if is_valid:
            COUNT += 1

print(COUNT)