#include <iostream>
#include <algorithm>
using namespace std;

const int mod = int(1e9) + 7;

class RockPaperScissorsMagicEasy { public: int count(vector<int> card, int score); };

vector<int> card;
int n, score;
vector<vector<int>> dp;
vector<vector<bool>> seen;

int rec(int i, int wincnt) {
  int &res = dp[i][wincnt];
  if(i == n) { return res = score == wincnt; }
  if(seen[i][wincnt]) { return res; }
  res = 0;
  int bob = card[i];
  for(int alice=0; alice<3; alice++) {
    int alice_win = (alice - bob + 3) % 3 == 2;
    res += rec(i+1, wincnt+alice_win);
    res %= mod;
  }
  seen[i][wincnt] = true;
  return res;
}

int RockPaperScissorsMagicEasy::
count(vector<int> _card, int _score) {
  card = _card;
  score = _score;
  n = card.size();
  dp.assign(2010, vector<int>(2010));
  seen.assign(2010, vector<bool>(2010));
  int res = rec(0, 0);
  return res;
}
    

#include <iostream>
#include <algorithm>
using namespace std;

class RockPaperScissorsMagicEasy { public: int count(vector<int> card, int score); };

const int mod = int(1e9) + 7;

int RockPaperScissorsMagicEasy::
count(vector<int> card, int score) {
  int n = card.size();
  vector<vector<int>> dp(2010, vector<int>(2010));
  dp[0][0] = 1;
  for(int i=0; i<n; i++) {
    int bob = card[i];
    for(int j=0; j<n; j++) {
      for(int alice=0; alice<3; alice++) {
        int alice_win = (alice - bob + 3) % 3 == 2;
        dp[i+1][j+alice_win] += dp[i][j];
        dp[i+1][j+alice_win] %= mod;
      }
    }
  }
  int res = dp[n][score];
  return res;
}