#!/usr/bin/env -S awk -f

{
	split($1, pos, "-")
	split($3, str, "")
	char = substr($2, 1, 1)

	# Count the frequency of char
	freq = 0
	if (str[pos[1]] == char)
		freq++
	if (str[pos[2]] == char)
		freq++

	if (freq == 1)
		count++
}

END { print count }