Problem:
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.

Sample Input 1

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

Sample Output 1

1

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

Sample Input 2

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

Sample Output 2

0

Katsusando's hypothesis turned out to be wrong.

Sample Input 3

1 30
3 5 10 30

Sample Output 3

3

Solution in Python (3.4.3) (judge verdict: Runtime Error)

# ｎとｍの取得
data = input().split()
n = int(data[0]) #n == 人数
m = int(data[1]) #m == 数字の種類
ans = 0
#ｎ回データを取得してカウント

j = 1 #j == 好きな数字
i = 1 #i == 行数カウンタ
c = [0] * m #c == ある数が含まれているかのカウンタ　0で初期化
    #データの取得

while i <= n:
    tmp = input()
    td = tmp[1:] #td == 好きな番号
    tn = tmp[0]  #tn == 好きな番号の数
    
    # 数字が含まれているかの比較
    while j <= m: # jがすべての数字について実行
        j = str(j)# jを文字列に変換
        if j in td: # jがｔｄに含まれるかの分岐
            j = int(j) #　ｊを数値に戻す
            c[j] += 1 # ｃのｊ番目の要素にカウント
        j = int(j) #if ではじかれたとき用にｊを数値に戻す
        j += 1# ｊをカウント
    j = 1    
    i += 1 # iをカウント

# 全てに含まれている数字の集計

for x in c:
    if x == n:
        ans += 1



print(ans)