easy
medium
hard
extreme
100

4+4

8

100

9+9

18

100

120+537

657

100

1,000+1,000

2,000

200

6+6

12

200

11+4

15

200

134+134

268

200

9,000+9,000

1,000,000

300

7+3

10

300

12+6

18

300

135+135

270

300

6,000+6,000

12,000

400

10+5

15

400

11+9

20

400

425+652

1,077

400

122+122

244

500

11+11

22

500

12+12

24

500

100+700

800

500

425+561

987