B - Foods Loved by Everyone

Score : $200$ points

Problem Statement

Katsusando loves omelette rice.

Besides, he loves crème brûlée, tenderloin steak and so on, and believes that these foods are all loved by everyone.

To prove that hypothesis, he conducted a survey on $M$ kinds of foods and asked $N$ people whether they like these foods or not.

The $i$-th person answered that he/she only likes the $A_{i1}$-th, $A_{i2}$-th, $...$, $A_{iK_i}$-th food.

Find the number of the foods liked by all the $N$ people.

Constraints

• All values in input are integers.
• $1 \leq N, M \leq 30$
• $1 \leq K_i \leq M$
• $1 \leq A_{ij} \leq M$
• For each $i$ $(1 \leq i \leq N)$, $A_{i1}, A_{i2}, ..., A_{iK_i}$ are distinct.

Constraints

Input is given from Standard Input in the following format:

$N$ $M$

$K_1$ $A_{11}$ $A_{12}$ $...$ $A_{1K_1}$

$K_2$ $A_{21}$ $A_{22}$ $...$ $A_{2K_2}$

$:$

$K_N$ $A_{N1}$ $A_{N2}$ $...$ $A_{NK_N}$

Output

Print the number of the foods liked by all the $N$ people.

3 4
2 1 3
3 1 2 3
2 3 2

1

As only the third food is liked by all the three people, $1$ should be printed.

5 5
4 2 3 4 5
4 1 3 4 5
4 1 2 4 5
4 1 2 3 5
4 1 2 3 4

0

Katsusando's hypothesis turned out to be wrong.

1 30
3 5 10 30

3