#include <iostream>
#include <vector>
using namespace std;
int main() {
vector<bool> a(202, false);
int n, diffNum, curVal;
cin >> n;
diffNum = n;
for(int i = 0; i < n; i++) {
cin >> curVal;
if(a[curVal + 100]) diffNum--;
else a[curVal + 100] = true;
}
cout << diffNum << endl;
}
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