Color Stripe

2000ms

262144K

Description:

A colored stripe is represented by a horizontal row of n square cells, each cell is pained one of k colors. Your task is to repaint the minimum number of cells so that no two neighbouring cells are of the same color. You can use any color from 1 to k to repaint the cells.

Input:

The first input line contains two integers n and k (1 ≤ n ≤ 5·10⁵; 2 ≤ k ≤ 26). The second line contains n uppercase English letters. Letter "A" stands for the first color, letter "B" stands for the second color and so on. The first k English letters may be used. Each letter represents the color of the corresponding cell of the stripe.

Output:

Print a single integer — the required minimum number of repaintings. In the second line print any possible variant of the repainted stripe.

Sample Input:

6 3
ABBACC

Sample Output:

2
ABCACA

Sample Input:

3 2
BBB

Sample Output:

1
BAB

Informação

Provedor Codeforces

Código CF219C