n=40;
grades=[|79,68,96|
38,58,92|
90,83,71|
87,68,39|
70,66,82|
62,75,58|
98,33,33|
96,65,89|
42,73,59|
82,91,85|
73,80,50|
70,60,32|
31,38,33|
30,55,71|
61,59,93|
85,97,91|
78,63,39|
71,33,59|
93,64,43|
45,41,62|
93,95,36|
57,49,63|
96,93,86|
92,66,65|
91,68,66|
98,97,44|
76,81,62|
34,68,97|
75,80,93|
50,58,47|
65,90,67|
46,50,64|
46,91,94|
76,40,49|
55,52,43|
84,84,33|
48,62,39|
66,86,97|
33,96,83|
56,39,56|];