https://www.acwing.com/problem/content/1232/

#include<bits/stdc++.h>
using namespace std;
const int N=100010;
int n,k;
int d[N];
long long int a[N];
long long int ans;
int main(){
    cin>>n>>k;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
   for(int i=1;i<=n;i++){
        a[i]+=a[i-1];
      // printf("ans=%d a[i]=%d a[i-1]=%d i=%d d=%d\n",ans,a[i],a[i-1],i,d[a[i-1]%k]);
        ans+=d[a[i]%k];
        d[a[i]%k]++;
    }
    cout<<ans<<endl;
    return 0;
}