#include <stdio.h>
#include <algorithm>
int N;
int main(){
    //input
    scanf("%d",&N);
    long A[N];
    for (int i = 0;i < N;i++){
        scanf("%ld",&A[i]);
    }

    //sort array A
    std::sort(A,A+N);

    //search
    int count = 0;
    for (long i = 0;i < N;i++){
        if (i == 0){
            if (A[i] != A[i+1]){
                count++;
            }
        }else if (i == N-1){
            if (A[i-1] != A[i]){
                count++;
            }
        }else{
            if (A[i-1] != A[i] && A[i] != A[i+1]){
                count++;
            }
        }
    }

    //output
    printf("%d\n",count);
    return 0;
}