cover

Problem Description

Tom wants to cover a rectangular floor by identical L-shape tiles without overlap. As shown below, the floor can be split into many small squares, and the L-shape tile consists of exactly four small squares. The floor of 3*8 can be completely covered by 6 L-shape tiles, but the floor of 3*7 is impossible.

111
1

11222344
15233364
15556664

Tom would like to know whether an arbitrary floor with n*m small squares can be completely covered or not. He is sure that when n and m are small he can find the answer by paper work, but when it comes to larger n and m, he has no idea to find the answer. Can you tell him?

Input

The input file will consist of several test cases. Each case consists of a single line with two positive integers m and n (1<=m<=15, 1<=n<=40).
The input is ended by m=n=0.

Output

For each case, print the word ‘YES’ in a single line if it is possible to cover the m*n floor, print ‘NO’ otherwise.

Sample Input

3 83 70 0

Sample Output

YESNO

#include<iostream>#include<cstdio>using namespace std;int main(){//freopen("a.txt","r",stdin);int n,m;while(cin>>n>>m&&n&&m){if(n==1||m==1) printf("NO\n");else{if(m*n%8) printf("NO\n");    else printf("YES\n");}}return 0;}