Light The Square
Time Limit: 5 Seconds
Memory Limit: 32768 KB
There is a new square been built in hangzhou,now in order to light the whole square in the night,it must need a lots of lights.
The government is lack of finance,so they want the the number of lights to be least.So they ask you to help.
To simplify the problem,the square can be see as a n��m rectangle. And lights are placed in this grids.If one grid has a light,its left, up, right, down grid can also be bright.Given m and n,Write a program to calculate the mininum number of lights.
The input file will contain one or more test cases,Each test case contains of one line containing two integers 0<n<150 and 0<m<9,separated by a space.The input file is end with m=n=0.and this case should not proceed.
For each test case,output one line "The square S need(s) L lights.",where S is the test case,L is the mininum number of this square.
The square 1 need(s) 1 lights.
The square 2 need(s) 2 lights.
The square 3 need(s) 3 lights.
Author: LAI, Chunbo
Source: ZOJ Monthly, October 2004