program main
	implicit none
    integer(8)::a,b,c,d,e,f
    read(*,*)a,b,c
    if(mod(a,2)==0 .or. mod(b,2)==0 .or. mod(c,2)==0)then
    	write(*,*) 0
    else
    	d=max(a,max(b,c))
        e=(d-1)/2
        f=e+1
        if(d==a)then
        	write(*,*) f*b*c-e*b*c
        else if(d==b)then
        	write(*,*) a*f*c-a*e*c
        else
        	write(*,*) a*b*f-a*b*e
        end if
    end if
    stop
end program main


