Bulbs

There are N bulbs connected in a row. Each bulb can display one of at most K colors. The number inside each circle represents the bulb's color.

Each bulb has a switch, so you may change that bulb to any color. When you change a bulb's color, every bulb connected to it on the left or right that had the same color before the change also changes. This continues until a bulb of a different color is reached.

For example, in the picture above, if bulb 4 is changed to color 2, bulbs 5 and 6 also change to color 2 because they were connected to bulb 4 with the same color. As a result, bulbs 4, 5, and 6 all become color 2, as shown below.

Given N and the initial colors of the bulbs, find the minimum number of color changes needed to make all bulbs have one identical color. Each color is represented by an integer from 1 to K.

The first line contains two positive integers N and K: the number of bulbs and the number of colors the bulbs can display. N is an integer from 1 to 200, and K is an integer from 1 to 20.

The second line contains N integers, separated by spaces, giving the colors of the bulbs in bulb-number order.

Print one integer: the minimum number of bulb color changes needed until all bulbs have the same color.