10
10
1+6/SS1S-9
SW4W*WWSWS
-W/W1WW/W3
S+S=S9-4+S
/W-W=WWSW=
4S2=S4-S*4
SW=W*WW+WS
3+S*S=2SW2
*W*W+WW+W*
S*3S4=S4+S