#include <stdio.h>

int main(void)
{
	int i, j, N, A[100000], num, a;
	scanf("%d", &N);
	for(i = 0;i < N;i++){
		scanf("%d", &A[i]);
	}
	for(i = 0;i < N - 1;i++){
		a = A[i];
		if(a == 0)continue;
		for(j = i + 1;j < N;j++){
			if(a == A[j]){
				A[j] = 0;
				A[i] = 0;
			}	
		}
		if(A[i] != 0)num++;
	}
	if(A[N - 1] != 0)num++;
	
	printf("%d\n", num);
	
	return 0;
}