import
java.io.*;
import
java.util.*;
import
java.util.Collections;
class
Pair {
int
first;
int
second;
public
Pair(
int
first,
int
second)
{
this
.first = first;
this
.second = second;
}
}
class
Pair_next {
int
first;
Pair second;
public
Pair_next(
int
first, Pair second)
{
this
.first = first;
this
.second = second;
}
}
class
cmp
implements
Comparator<Pair_next> {
public
int
compare(Pair_next p1, Pair_next p2)
{
return
p2.first - p1.first;
}
}
public
class
GFG {
static
double
sumMaxDistances(
int
X[],
int
Y[],
int
N,
int
K)
{
Vector<Pair_next> distances
=
new
Vector<Pair_next>();
for
(
int
i =
0
; i < N; i++) {
for
(
int
j = i +
1
; j < N; j++) {
int
d = (X[i] - X[j]) * (X[i] - X[j])
+ (Y[i] - Y[j]) * (Y[i] - Y[j]);
Pair temp_pair =
new
Pair(i, j);
Pair_next temp
=
new
Pair_next(d, temp_pair);
distances.add(temp);
}
}
double
ans =
0
;
Collections.sort(distances,
new
cmp());
for
(
int
i =
0
; i < N; i++) {
int
mx = -
1
;
int
cnt =
0
;
for
(
int
j =
0
; j < distances.size(); j++) {
if
(distances.get(j).second.first != i
&& distances.get(j).second.second
!= i) {
cnt++;
}
if
(cnt == K) {
mx = distances.get(j).first;
break
;
}
}
if
(mx != -
1
) {
ans += Math.sqrt(mx);
}
}
return
ans;
}
public
static
void
main(String[] args)
{
int
X[] = {
0
,
1
,
1
};
int
Y[] = {
0
,
0
,
1
};
int
K =
1
;
int
N = X.length;
System.out.println(sumMaxDistances(X, Y, N, K));
}
}