from string import ascii_letters

DEBUG=False

def debug(*args):
    if DEBUG:
        print(args)

def within(first, second):
    if ((first[0] <= second[0] and first[1] >= second[1])
        or (second[0] <= first[0] and second[1] >= first[1])):
        return True
    return False

def main():
    with open("input4.txt", "r") as file:
        inlines = [line.strip() for line in file.readlines()]

    overlaps = []
    range_pairs = []
    for line in inlines:
        first, second = line.split(",")
        sfirst = first.split("-")
        pfirst = (int(sfirst[0]), int(sfirst[1]))
        ssecond = second.split("-")
        psecond = (int(ssecond[0]), int(ssecond[1]))
        
        if within(pfirst, psecond):
            overlaps.append(1)
        else:
            overlaps.append(0)

        range_pairs.append((pfirst, psecond))
    
    print(sum(overlaps))


if __name__ == "__main__":
    main()