#!/usr/bin/env python

import re

RE_LINE = re.compile("^(\d+)-(\d+)\s+(.):\s+(.*)$")

valid = 0
with open("input01.txt","r") as f:
	for line in f:
		m = RE_LINE.match(line.strip())
		if not m:
			print(line)
			continue
		(pmin, pmax) = (int(m.group(1)), int(m.group(2)))
		(pch, pline) = (m.group(3), m.group(4))
		tmp = pline[pmin-1] + pline[pmax-1]
		if tmp.count(pch) == 1:
			valid +=1

print(valid)