qq
6
68
991
152o99
18
5
()
1
3
ab
=2nac1+b
2c12+2b
-=2c1-+b
2c12+2ki=2kc1+i2c12+2i-=2c1-+i2b
2+2ki=2kb
+i2b
2+2i-=2b
-+i2
167