31 lines
727 B
ObjectPascal

var f:array[0..100,0..50]of longint;
a:array[0..100]of longint;
i,j,n,k,l,t:longint;
function min(x,y:longint):longint;
begin
min:=x;
if min>y then min:=y;
end;
begin
assign(input,'chop.in');reset(input);
assign(output,'chop.out');rewrite(output);
readln(n,k);
k:=k+3;
for i:=1 to n do read(a[i]);
for i:=1 to n-1 do
for j:=i+1 to n do
if a[i]>a[j] then
begin
t:=a[i];a[i]:=a[j];a[j]:=t;
end;
fillchar(f,sizeof(f),$7F div 3);
f[0,0]:=0;
for i:=1 to n do
for j:=1 to k do
for l:=1 to i-1 do
f[i,j]:=min(f[i-1,j],f[l-1,j-1]+sqr(a[i]-a[l]));
if k*2>n then writeln(-1)
else writeln(f[n,k]);
close(input);close(output);
end.