张老师为“数学竞赛”获奖的同学买奖品．张老师买了两盒钢笔，给每名获奖的同学发一枝，一共有{#blank#}1{#/blank#}名同学获了奖？

6+3=                7-5=                 4+4=                  9-5=

10-2=               5+5=                 6-1=                  2+6=

5+8=               10-4=                3+7=                  9-1=

8-6=                7+7=                 5-4=                   3+4=

5+6=               8-4=                  3+3=                  9-8=

10-9=              8+1=                  6-2=                  2+10=

6+6=               4-1=                  7+9=                  3-3=

9-7=                8+8=                  6-3=                  5+2=

3+5=               10-3=                  4+6=                  7-1=

8-2=                2+4=                  6-6=                  5+7=

6+9=                9-3=                 10+3=                  7-4=

8-3=                9+10=                 5-2=                  4+9=

7+8=                10-6=                 2+7=                  8-5=

6-4=                 2+3=                 3-2=                   4+5=

6+8=                8-7=                  10+7=                  5-3=

10-8=                8+2=                  9-2=                   3+9=

5+9=                10-5=                  8+10=                 7-3=

5-1=                  3+8=                 9-6=                   6+7=

9+9=                  7-2=                  6+10=                 10-7=

6-5=                  8+9=                  9-4=                   4+8=

13+<20        10->9-5

10+<15        11+4<18-

12+<18        19->3+6