{"raw_statement":[{"iden":"problem statement","content":"We have $N$ slices of toast and $M$ plates. $M$ is an integer between $\\frac{N}{2}$ and $N$, inclusive. The $i$\\-th slice of toast has a deliciousness of $A_{i}$.\nLet us put the $N$ slices of toast on the $M$ plates to satisfy the following two conditions.\n\n*   Each plate can have at most two slices of toast on it.\n*   Every slice of toast is on some plate.\n\nLet $B_{j}$ be the sum of the deliciousness of the toast on the $j$\\-th plate ($0$ if the plate has no toast on it). Then, let the **unbalancedness** be $\\sum_{j=1}^{M} B_{j}^{2}$.\nFind the minimum possible value of the unbalancedness."},{"iden":"constraints","content":"*   $1\\leq N\\leq 2\\times 10^{5}$\n*   $\\frac{N}{2}\\leq M\\leq N$\n*   $1\\leq A_{i}\\leq 2\\times 10^{5}$\n*   All input values are integers."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$N$ $M$\n$A_{1}$ $A_{2}$ $\\cdots$ $A_{N}$"},{"iden":"sample input 1","content":"5 3\n1 1 1 6 7"},{"iden":"sample output 1","content":"102\n\nIf you put the first and second slices on the first plate, the third and fourth slices on the second plate, and the fifth slice on the third plate, we have $(1+1)^{2}+(1+6)^{2}+7^2=102$, so the unbalancedness is $102$.\nThere is no way to put them to make the unbalancedness less than $102$, so print $102$.\nNote that you cannot put the first, second, and third slices on the same plate."},{"iden":"sample input 2","content":"2 1\n167 924"},{"iden":"sample output 2","content":"1190281"},{"iden":"sample input 3","content":"12 9\n22847 98332 854 68844 81080 46058 40949 62493 76561 52907 88628 99740"},{"iden":"sample output 3","content":"61968950639"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}