#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sat Dec 29 14:37:16 2018

@author: harriet
"""

#Given a string, return the count of the number of times that a substring length 2 appears in the string and also as the last 2 chars of the string, so "hixxxhi" yields 1 (we won't count the end substring).
#
#
#last2('hixxhi') → 1
#last2('xaxxaxaxx') → 1
#last2('axxxaaxx') → 2

def last2(str):
  if len(str) < 2:
    return 0

  end_chars=str[-2:]

  count=0

  for i in range(len(str)-2):
    sub = str[i:i+2]
    if sub == end_chars:
      count=count+1

  return count