A flea is sitting at one of the *n* hassocks, arranged in a circle, at the moment. After minute number *k* the flea jumps through *k* - 1 hassoсks (clockwise). For example, after the first minute the flea jumps to the neighboring hassock. You should answer: will the flea visit all the hassocks or not. We assume that flea has infinitely much time for this jumping.
The only line contains single integer: 1 ≤ *n* ≤ 1000 — number of hassocks.
    x=input('Enter the first number of squares')
    y=input('Enter the second number of squares')
    if x%2==0:
      print(x//2*y)
    elif y%2==0:
      print(y//2*x)
    else:
      print((y//2*x)+x//2)