#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#  journals.py
#  
#  Copyright 2022 ACM CTU Contest Team 53 <cteam053@acm-new.fiit.stuba.sk>
#  
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#  
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#  
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#  
#  


def main(args):
	z = input().strip().split()
	n = len(z)
	cnt_flips = n
	for i in range(n - 1):
		if (z[i] != z[i + 1]):
			cnt_flips -= 1
	print(cnt_flips // 2) 
	return 0

if __name__ == '__main__':
	import sys
	sys.exit(main(sys.argv))