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 if(a == 1 .and. b == 15) then
 print *, '*'
else if(a == 15 .and. b == 1) then
 print *, '*'
else
 print *, 'x'
end if
 
end program r20718f