#include<stdio.h>
#include <stdlib.h>
 
int main()
{
	int arr[1000],i,j,n,count=0, min;
	scanf("%d",&n);
	for(i=0;i<n;i++)
	{
		scanf("%d",&arr[i]);
	}
 
	for(i=0;i<n;i++)
	{
		min = i;
		for(j=i+1;j<n;j++)
		{
			if(arr[min]>arr[j])
			{
				min = j;	
			}
		}
		{
			int temp = arr[min];
			arr[min] = arr[i];
			arr[i] = temp;
		}
	}
 
	for(i=1;i<n;i++)
	{
		if(arr[i]==arr[i-1])
		{
			count++;
			while(arr[i]==arr[i-1]) i++;
		}
	}
 
	printf("%d",count);
 
	return 0;
}
 
 

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