**看不懂的私信我
#include <bits/stdc++.h>
using namespace std;
int main()
{
int n;
cin >> n;
int q[n+1], a[n+1], cnt = 1;
for(int i = 1; i <= n; i ++)
cin >> q[i];
sort(q+1, q+n+1);
q[0] = -1;
for(int i = 1; i <= n; i ++ )
{
if(q[i] != 0)
{
if(q[i] != q[i-1]) a[cnt ++] = q[i];
}
}
cout << cnt - 1;
return 0;
}