Sadness value

Satyanand is at a medical shop. He is diagnosed with a disease. There is a rack of medicines in the shop. Let there be $N$ medicines on the rack. Let the value associated with $ith$ medicine be $a$i The doctor told him that three medicines available in the medical shop will cure his disease. But Satyanand wants to select only those medicines $i$, $j$, $k$ from the rack such that $i$ $i $j $k where