2 + 4

(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

3 + 2

(a)  

5 + 2

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(a)  

11 + 2

(a)  

13 + 2

(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

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(a)  

11 + 3

(a)  

13 + 3

(a)  

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4 + 18

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7 + 4

(a)  

9 + 4

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11 + 4

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13 + 4

(a)  

15 + 4

(a)  

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(a)  

19 + 4

(a)  

5 + 6

(a)  

5 + 8

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(a)  

5 + 14

(a)  

5 + 16

(a)  

5 + 18

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(a)  

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7 + 5

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9 + 5

(a)  

11 + 5

(a)  

13 + 5

(a)  

15 + 5

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(a)  

6 + 16

(a)  

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(a)  

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(a)  

9 + 6

(a)  

11 + 6

(a)  

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17 + 6

(a)  

19 + 6

(a)  

21 + 6

(a)  

7 + 8

(a)  

7 + 10

(a)  

7 + 12

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7 + 14

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7 + 16

(a)  

7 + 18

(a)  

7 + 20

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9 + 7

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11 + 7

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13 + 7

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15 + 7

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8 + 8

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8 + 18

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8 + 20

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11 + 8

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13 + 8

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9 + 20

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15 + 9

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11 + 12

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13 + 20

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15 + 13

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19 + 13

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14 + 14

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14 + 16

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14 + 18

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14 + 20

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15 + 14

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17 + 14

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19 + 14

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21 + 14

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15 + 16

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15 + 20

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16 + 20

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17 + 16

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19 + 16

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17 + 18

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17 + 20

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19 + 17

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21 + 17

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18 + 18

(a)  

18 + 20

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19 + 18

(a)  

21 + 18

(a)  

19 + 20

(a)  

19 + 19

(a)  

21 + 19

(a)  

20 + 20

(a)  

21 + 20

(a)