#include <bits/stdc++.h>
using namespace std;
 
#define ms(s,n) memset(s,n,sizeof(s))
#define all(a) a.begin(),a.end()
#define present(t, x) (t.find(x) != t.end())
#define sz(a) int((a).size())
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORd(i, a, b) for (int i = (a) - 1; i >= (b); --i)
#define pb push_back
#define pf push_front
#define fi first
#define se second
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef vector<pi> vii;
 
const int MOD = (int) 1e9+7;
const int INF = (int) 1e9+1;
inline ll gcd(ll a,ll b){ll r;while(b){r=a%b;a=b;b=r;}return a;}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
 
 
int main(){
	#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	#endif
	int n; cin >> n;
	ll sum = 0;
	ll ans = 0;
	int cnt[n+1] ={0};
	cnt[0] = 1;
	for(int i = 0; i < n; i++){
		int x; cin >> x;
		sum += x;
		int remain = (sum % n + n) % n;
		if(cnt[remain]) ans += cnt[remain];
		cnt[remain]++;
	}
	cout << ans << endl;
	return 0;
}

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100
2 1 -3 2 -7 7 -2 6 9 -4 10 -6 3 9 -8 7 -2 -9 4 -3 -2 6 6
3 7 2 -1 10 6 -4 4 9 -1 -5 -6 -9 1 2 2 -10 -2 3 3 4 3 -
6 -5 -1 9 6 -4 6 2 -1 6 1 6 1 3 7 -6 10 1 1 6 -9 0 5 -1
8 6 0 5 5 -3 1 1 -5 -9 -8 -9 -7 7 -6 10 7 8 1 -2 2 8 9 -
1 5 -7 3 -3 -9 -3 4