#include <stdio.h>
#include <stdlib.h>
int max(int a,int b){
    if(a>=b)return a;
    else return b;
}

typedef struct node{
    int r;
    int h;
}node;

struct node yuan[10000];
struct node back[10000];
int n;
int k;


int cmp(const void*a,const void*b){
    struct node a1=*(struct node*)a;
    struct node b1=*(struct node*)b;
    return 2*b1.r*b1.h-2*a1.r*a1.h;
}


int work(int x){
    int m=0;
    for(int i=0;i<n;i++){
        if(yuan[i].r<=yuan[x].r&&i!=x){
            back[m++]=yuan[i];
        }
    }
    if(m<k-1)return 0;
    qsort(back,m,sizeof(struct node),cmp);
    int sum=0;
    for(int i=0;i<k-1;i++){
        sum+=2*back[i].r*back[i].h;
    }
    sum+=2*yuan[x].r*yuan[x].h+yuan[x].r*yuan[x].r;
    return sum;



}

int main()
{
    scanf("%d%d",&n,&k);
    for(int i=0;i<n;i++){
        scanf("%d %d",&yuan[i].r,&yuan[i].h);
    }
    int ans=0;
    for(int i=0;i&...