0字开头:000,001,002,010,011,012,020,021,022
1字开头:100,101,102,110,111,112,120,121,122
2字开头:200,201,202,210,211,212,220,221,222
共有:3x9=27(个)
0字开头:000,001,002,010,011,012,020,021,022
1字开头:100,101,102,110,111,112,120,121,122
2字开头:200,201,202,210,211,212,220,221,222
共有:3x9=27(个)