from typing import List, Set
from collections import Counter

def find_min_table(table: List[str], chars: Set[str]) -> int:
    for idx in range(len(table) - 1):
        if table[idx] != table[idx + 1]:
            return min(
                [len(table)] +
                [find_min_table(table[: idx] + [k] + table[idx + 2:], chars)
                    for k in chars if k != table[idx] and k != table[idx + 1]]
                )

    # Brak mozliwosci jakiejkolwiek zmiany
    return len(table)

if __name__ == '__main__':

    initial_array = ['a', 'b', 'c']
    chars = set(initial_array)

    # Sortowanko z kluczem
    counter = Counter(initial_array)
    initial_array = sorted(initial_array, key=lambda x: counter[x], reverse=True)

    # Rek
    print(find_min_table(initial_array, chars))