Grouping#4599
You are given integers a = \{a_i\}. Let b = \{b_j\} be such numbers (not necessarily integers), that:
such that is minimized.
Find .
First line contains two numbers and . Second line contains exactly integers — \{a_i\}.
Only real number with absolute or relative error not greater than 10^{-8}.
Limits
1 \leq N \leq 5000
1 \leq K \leq N
0 \leq a_i \leq 400000
Example 1