#!/usr/bin/env python3

INPUT_FILE = 'input'

def main():
    content = map(str.strip,  open(INPUT_FILE, 'r').readlines())
    includes = 0
    for line in content:
        e1, e2 = line.split(',')
        e1_from, e1_to = map(int, e1.split('-'))
        e2_from, e2_to = map(int, e2.split('-'))
        #r1 = range(int(e1_from), int(e1_to) +1)
        #r2 = range(int(e2_from), int(e2_to) +1)
        if (e1_from <= e2_from and e1_to >= e2_to ) or \
        ( e2_from <= e1_from and e2_to >= e1_to ):
            includes += 1
    print(includes)

if __name__ == '__main__':
    main()