for i = 1 to n
    int temp0 = dp[0], temp1 = dp[1], temp2 = dp[2], temp3 = dp[3];
    temp0 = ( dp[1] + dp[2] ) % MOD + dp[3];
    temp1 = ( dp[0] + dp[2] ) % MOD + dp[3];
    temp2 = ( dp[0] + dp[1] ) % MOD + dp[3];
    temp3 = ( dp[0] + dp[1] ) % MOD + dp[2];
    dp[0] = temp0 % MOD;
    dp[1] = temp1 % MOD;
    dp[2] = temp2 % MOD;
    dp[3] = temp3 % MOD;
The answer is dp[3].