Luke is daydreaming in Math class. He has a sheet of graph paper with rows and columns, and he imagines that there is an army base in each cell for a total of bases. He wants to drop supplies at strategic points on the sheet, marking each drop point with a red dot. If a base contains at least one package inside or on top of its border fence, then it's considered to be supplied. For example:
Given and , what's the minimum number of packages that Luke must drop to supply all of his bases?
Two space-separated integers describing the respective values of and .
Print a single integer denoting the minimum number of supply packages Luke must drop.
Sample Input 0
Sample Output 0
Luke has four bases in a grid. If he drops a single package where the walls of all four bases intersect, then those four cells can access the package:
Because he managed to supply all four bases with a single supply drop, we print as our answer.