#include<bits/stdc++.h>
using namespace std;
#define INF 0x3f3f3f3f
struct node {
double x, y;
int id;
node(double x_ = 0, double y_ = 0, int id_ = 0) {
x = x_;
y = y_;
id = id_;
}
};
vector<node> v[10010];
vector<node> cnt;
int vis[10010];
int tot;
node tmp;
int n, num;
double distance(node x, node y) {
return sqrt((x.x - y.x) * (x.x - y.x) + (x.y - y.y) * (x.y - y.y));
}
int main() {
cin >> n >> num;
for(int i = 1; i <= n; i++) {
cin >> tmp.x >> tmp.y;
tmp.id = i;
v[1].push_back(tmp);
}
double maxx, sum, cntsum;
int id, cntid;
int flag;
double cntmin0, cntmin1;
for(int i = 1; i <= num - 1; i++) {
maxx = 0;
for(int j = 1; j <= i; j++) {
for(int k = 0; k < v[j].size(); k++) {
for(int l = k + 1; l < v[j].size(); l++) {
if(distance(v[j][k], v[j][l]) > maxx) {
maxx = distance(v[j][k], v[j][l]);
id = j;
}
}
}
}
tot = v[id].size();
cnt.clear();
for(int j = 0; j < v[id].size(); j++) cnt.push_back(v[id][j]), vis[j] = 0;
v[id].clear();
cntsum = 0;
for(int j = 0; j < cnt.size(); j++) {
sum = 0;
for(int k = 0; k < cnt.size(); k++) {
if(j == k) continue;
sum += distance(cnt[j], cnt[k]);
}
if(sum > cntsum) {
cntsum = sum;
cntid = j;
}
}
vis[cntid] = 1;
flag = 1;
while(flag) {
flag = 0;
for(int j = 0; j < tot; j++) {
if(vis[j]) continue;
cntmin0 = cntmin1 = INF;
for(int k = 0; k < tot; k++) if(vis[k] == 0 && k != j) cntmin0 = min(cntmin0, distance(cnt[j], cnt[k]));
for(int k = 0; k < tot; k++) if(vis[k] == 1 && k != j) cntmin1 = min(cntmin1, distance(cnt[j], cnt[k]));
if(cntmin0 != INF && cntmin1 <= cntmin0) {
flag = 1;
vis[j] = 1;
break;
}
}
}
for(int j = 0; j < tot; j++) {
if(vis[j]) {
v[i + 1].push_back(cnt[j]);
} else {
v[id].push_back(cnt[j]);
}
}
}
for(int i = 1; i <= num; i++) {
cout << i << ":\n";
for(int j = 0; j < v[i].size(); j++)
cout << v[i][j].id << " " << v[i][j].x << " " << v[i][j].y << endl;
}
return 0;
}
/*
9 4
7 2
3 8
4 5
2 1
2 7
3 4
3 5
4 4
4 5
*/
