#include <stdio.h>

#include <stdlib.h>




int comp(const void *arg1, const void *arg2){

	return *(int *)arg1 - *(int *)arg2;

}



int main(void) {
	int i,n,a[100000],count=0;
	scanf("%d",&n);

	for(i=0;i<n;i++){
		scanf("%d",&a[i]);
	}

	qsort(a, n, sizeof(int), comp);

	for(i=0;i<=n;i++){
		if(a[i-1]!=a[i] && a[i]!=a[i+1])	count++;
	}
	printf("%d\n",count);
	return 0;

}