In the popular card game *SET*, the player's goal is to identify a certain triplet
of cards with some special properties, called a *set*. Each card shows some figures,
which differ in number, shape, transparency and color.

Marin and Josip have recently bought a deck of these cards and now they can't
stop playing. They've become so skilled at noticing *sets* that it soon became boring that the cards are
determined by only four properties. Thus, they have decided to have fun with a generalized version of the
game.

At their disposal is a deck of **different** cards. Each card is represented by a sequence of characters,
each being one of `1`

, `2`

or `3`

. The order of the cards in the deck does not matter.

An unordered triplet of cards is called a *set* if for each of the positions, the three characters corresponding
to the three cards are either the same or pairwise different. For example, three cards represented by `1123`

,
`1322`

and `1221`

make a *set* because all of the characters in the first and third positions are the same (`1`

and `2`

respectively), and the characters in the second and fourth positions are different (`1`

, `2`

and `3`

in
some order).

While looking at these cards on the table, they started to wonder: how many unordered triplets of these cards make a set. Write a program which will answer their question.

#### Constraints

In every subtask, it holds that and .

Subtask | Points | Constraints |
---|---|---|

1 | 10 | |

2 | 30 | |

3 | 70 | No additional constraints. |

#### Input Specification

The first line contains the integers and , the number of cards in the deck and the number of properties of a single card, respectively.

Each of the following lines contains a sequence of characters representing a card. Each character is
one of `1`

, `2`

or `3`

. Different lines contain different sequences of characters.

#### Output Specification

In the only line, print the number of unordered triplets which form a *set*.

#### Sample Input 1

```
3 4
1123
1322
1221
```

#### Sample Output 1

`1`

#### Sample Input 2

```
2 2
11
22
```

#### Sample Output 2

`0`

#### Sample Input 3

```
5 3
111
222
333
123
132
```

#### Sample Output 3

`2`

#### Explanation for Sample Output 3

The two sets are `111`

, `222`

, `333`

and `111`

, `123`

, `132`

.

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