#include <iostream>
#include <vector>

using namespace std;

int main(){
    int n;
    cin>>n;

    vector<int> nums(3, 0);

    int a;
    for(int i=0;i<n;i++){
        cin>>a;
        nums[a%3]++;
    }

    int ans=0;

    ans+=nums[0]*(nums[0]-1)*(nums[0]-2)/6;
    ans+=nums[1]*(nums[1]-1)*(nums[1]-2)/6;
    ans+=nums[2]*(nums[2]-1)*(nums[2]-2)/6;

    ans+=nums[0]*nums[1]*nums[2];

    cout<<ans;
}