#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
int main() {
    ll n, k;
    cin >> n >> k;
    vector<ll> a(n + 1), prefix(n + 1);
    for (ll i = 1; i <= n; i++){
    	cin >> a[i];
    	prefix[i] = prefix[i-1] + a[i];
    }
 
    unordered_map<ll, ll> freq;
    freq[0] = 1; ll c = 0;
 
    for (ll j = 1; j <= n; j++) {
        ll y = ( (prefix[j] % k - j % k + k) % k );
        if(freq.find(y)!=freq.end()){
			c = c + freq[y];
		}
 
        freq[y]++;
    }
    cout << c << "\n";
}