pairs = [[[int(n) for n in m.split("-")] for m in l.split(",")] for l in [i for i in open("input.txt", 'r').read().splitlines()]]

sum = 0

for p in pairs:
    if p[0][0] <= p[1][0] and p[0][1] >= p[1][1]:
        sum += 1
    elif p[0][0] >= p[1][0] and p[0][1] <= p[1][1]:
        sum += 1

print(sum)