program r20718f
 
implicit none
integer :: a, b
 
read *, a, b

if(b == 15 - a) then
 print *, '+'
else if(a == 3 .and. b == 5) then
 print *, '*'
else if(a == 5 .and. b == 3) then
 print *, '*'
else
 print *, 'x'
end if

end program r20718f