#include <iostream>
#include <map>
using namespace std;
int main() {
long long n;
cin>>n;
long long a[n];
for(long long i=0;i<n;i++)
{
cin>>a[i];
}
long long sum=0;
long long count1=0;
map<long long,long long> Map;
Map[0]=1;
for(long long i=0;i<n;i++)
{
sum=((sum+a[i])%n+n)%n;
if(Map.count(sum) > 0)
{
count1+=Map[sum];
}
if(Map.count(sum) <= 0)
{
Map[sum]=1;
}
else
{
Map[sum]++;
}
}
cout<<count1<<endl;
return 0;
}
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MTAwCjEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDEgMSAxIDE=
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