In order to improve their physical fitness, the cows have taken up gymnastics!
Farmer John designates his favorite cow Bessie to coach the $N$ other cows and
to assess their progress as they learn various gymnastic skills.

In each of $K$ practice sessions ($1 \leq K \leq 10$), Bessie ranks the $N$ cows according to their
performance ($1 \leq N \leq 20$). Afterward, she is curious about the consistency in these rankings.
A pair of two distinct cows is consistent if one cow did better than the
other one in every practice session.

Help Bessie compute the total number of consistent pairs.

INPUT FORMAT:
The first line of the input file contains two positive integers $K$ and $N$. The next $K$ lines will each contain the
integers $1 \ldots N$ in some order, indicating the rankings of the cows (cows
are identified by the numbers $1 \ldots N$). If $A$ appears before $B$ in one of
these lines, that means cow $A$ did better than cow $B$.

OUTPUT FORMAT:
Output, on a single line, the number of consistent pairs.

SAMPLE INPUT:
3 4
4 1 2 3
4 1 3 2
4 2 1 3
SAMPLE OUTPUT:
4

The consistent pairs of cows are $(1,4)$, $(2,4)$, $(3,4)$, and $(1,3)$.

Problem credits: Nick Wu

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