,
- :
(
300
600
900
1200
1500
1800
2100
2400
2700
3000
)
1
...
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
...
2069
:
3 . .
. 1 . 21
2
8-
1-4
1-
7
4
3
()
- Lets practise!
1
...
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
...
2069
: