#include <iostream>
using namespace std;
int main() {
// your code goes here 1/n n=1..100 1/n^2
int n,x;
cin>>n;
int s=0;
for(int i=0;i<=n;i++){
cin>>x;
if (x>0){
s=s+x;
}
}
cout<<s;
return 0;
}
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