#!/usr/bin/env python

def build_range(text):
    first, last = text.split("-")
    return range(int(first), int(last)+1)

count = 0

with open('input') as f:
    for line in f:
        aS, bS = line.rstrip().split(",")
        a = build_range(aS)
        b = build_range(bS)

        if (a[0] in b and a[-1] in b) or (b[0] in a and b[-1] in a):
            count = count + 1

print(count)