Costume Party#10148
It's Halloween! Farmer John is taking his cows to a costume party, but unfortunately, he has only one costume. The costume can fit exactly two cows, with a total length of at most .
Farmer John has cows, numbered . Cow has length l_i~(1 \le l_i \le 10^6).
Two cows can fit into the costume if the sum of their lengths is no greater than the length of the costume.
FJ wants to know how many pairs of distinct cows can fit into the costume.
The first line contains two integers n~(2 \le n \le 20000) and s~(1 \le s \le 10^6). Each of the next lines contains one integer L_i~(1 \le i \le n), representing the length of cow .
Print one integer representing the number of pairs of cows that can fit into the costume. The order of the two cows does not matter.
Example 1