A famous advertisement slogan says, "If liver is healthy, then life is colorful. If liver is ill, then life is black and white." A healthy person and a ill person may get different feelings within the same view. In order to understand the difference, you are asked to transform a colorful image to a grayscale image. The transform formula for each pixel is:

round( (RED + GREEN + BLUE) / 3) = GRAY

RED, GREEN, and BLUE stands for the intensity level of the colorful image. Similiarly, GRAY stands for the intensity level of the grayscale image.

「肝若是好，人生是彩色的；肝若不好，人生是黑白的。」身心健康的人和不健康的人，對於世界的感受通常有很大的差異。為了讓各位深刻體會這份差異，現在要請大家將一張彩色圖片轉換成灰階圖片。轉換的方式如下：

round( (RED + GREEN + BLUE) / 3) = GRAY

round是指四捨五入至個位數。RED、GREEN、BLUE是指彩色圖片的像素亮度，GRAY是指灰階圖片的像素亮度。