Taco Grid Coverage

In this problem, you are given a grid with ( n ) rows and ( m ) columns. Your task is to determine the minimum number of turns required to cover the entire grid. It has been proven that the answer is given by the formula ( \left\lfloor \frac{n \times m + 1}{2} \right\rfloor ). This problem tests basic arithmetic operations and careful handling of inputs and outputs.

inputFormat

The input consists of two integers ( n ) and ( m ) separated by space, representing the number of rows and columns of the grid respectively. The input is read from standard input (stdin).

outputFormat

Output a single integer which is the minimum number of turns required to cover the grid, printed to standard output (stdout).## sample

1 1

1