In _K-city_ , there are n streets running east-west, and m streets running north-south. Each street running east-west and each street running north-south cross each other. We will call the smallest area that is surrounded by four streets a block. How many blocks there are in K-city?
a,b=map(int,input().split())
print((a*b)/2)
a,b=map(int,input().split())
print((a-1)*(b-1))