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D. Sereja and Sets
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Sereja has m non-empty sets of integers A1, A2, ..., Am. What a lucky coincidence! The given sets are a partition of the set of all integers from 1 to n. In other words, for any integer v (1 ≤ v ≤ n) there is exactly one set At such that . Also Sereja has integer d.

Sereja decided to choose some sets from the sets he has. Let's suppose that i1, i2, ..., ik (1 ≤ i1 < i2 < ... < ik ≤ m) are indexes of the chosen sets. Then let's define an array of integers b, sorted in ascending order, as a union of the chosen sets, that is, . We'll represent the element with number j in this array (in ascending order) as bj. Sereja considers his choice of sets correct, if the following conditions are met:

b1 ≤ dbi + 1 - bi ≤ d (1 ≤ i < |b|); n - d + 1 ≤ b|b|.

Sereja wants to know what is the minimum number of sets (k) that he can choose so that his choice will be correct. Help him with that.

Input

The first line contains integers n, m, d (1 ≤ d ≤ n ≤ 105, 1 ≤ m ≤ 20). The next m lines contain sets. The first number in the i-th line is si (1 ≤ si ≤ n). This number denotes the size of the i-th set. Then the line contains si distinct integers from 1 to n — set Ai.

It is guaranteed that the sets form partition of all integers from 1 to n.

Output

In a single line print the answer to the problem — the minimum value k at the right choice.

Examples
Input
3 2 21 22 1 3
Output
1
Input
5 1 15 4 5 3 2 1
Output
1
Input
7 3 14 1 3 5 72 2 61 4
Output
3