#include<bits/stdc++.h>
using namespace std ;
int main ( )
{
	long long n , s = 0 , b = 0 ;
	cin >> n ;
	long long a [n] ;
	for ( int i = 0 ; i < n ; i ++ )
	{
		cin >> a [i] ;
	} 
	s = a [0] ;
	for ( int j = 0 ; j < n ; j ++ )
	{
		if ( a [j] == s )
		{
			s == a [j] ;
			b ++ ;
		}
		if ( a [j] != s )
		{
			s = a [j] ;
		}
	}
	cout << b ;
	return 0;
}