Election

Given the voting preferences of a population of $M$ people, determine the winner of an election among $N$ candidates numbered $1, \dots, N$. The $M$ people are partitioned into $G$ "groups," where all members of a group share the same voting preferences. Each group's preferences are given by listing the candidates from most preferred to least preferred. The result is determined by an instant-runoff voting procedure.

In this method, the current first choices of the $M$ people are counted, and the candidate with the fewest votes is eliminated. If several candidates tie for the fewest votes, the highest-numbered among them is eliminated. The eliminated candidate is then removed from every person's preference list, and again the candidate with the fewest votes is eliminated. This repeats until only one candidate remains, who is the winner.

The input contains multiple test cases. Each test case begins with a line containing two integers $G$ and $N$ ($2 \le N \le 5$, $1 \le G \le 20$). The next $G$ lines each have the form $M_i\ a_{i1}\ a_{i2}\ \dots\ a_{iN}$, where $1 \le M_i \le 20$ and $a_{i1}, \dots, a_{iN}$ is a permutation of $1, \dots, N$. Here $M_i$ is the number of people in the $i$-th group, and $a_{i1}, \dots, a_{iN}$ orders the $N$ candidates from most to least preferred for that group. The end of input is marked by a test case with $G = N = 0$, which should not be processed.

For each test case, print the winner of the election on its own line.