data = []

file = open('input.txt','r')
for s in file:
    val = s.split(':')
    data.append(val)

valid = 0
for d in data:
    search = d[0][-1]
    amount = d[0].replace(' ' + search,'').split('-')
    low  = int(amount[0])
    high = int(amount[1])
    count = 0
    if (d[1][low] == search) != (d[1][high] == search):
        valid += 1
print(valid)