def cutter(n,m):
    if(n==1):
        return m-1
    elif(m==1):
        return n-1
    elif(n>=m):
        if(n%2==1):
            return cutter(n/2+1,m) + cutter(n/2,m)
        else:
            return 2*cutter(n/2,m)
    else:
        if(m%2==1):
            return cutter(n,m/2+1) + cutter(n,m/2)
        else:
            return 2*cutter(n,m/2)        
        
#!/bin/python

import sys


n,m = raw_input().strip().split(' ')
n,m = [int(n),int(m)]

print (n-1)*m+m-1