The blocks in the city of Fishburg are of square form. N avenues running south to north and M streets running east to west bound them. A helicopter took off in the most southwestern crossroads and flew along the straight line to the most northeastern crossroads. How many blocks did it fly above?
Note. A block is a square of minimum area (without its borders).
The input contains N and M separated by one or more spaces.
1 < N, M < 32000.
The number of blocks the helicopter flew above.
Problem Source: Quarterfinal, Central region of Russia, Rybinsk, October 17-18 2001