#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;
// mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
#define MAXN 200007
const ll inf = 1e17 ;
int n , k ;
pair < int , int > a[ MAXN ] ;
pair < int , int > srt[ MAXN ] ;
int ord[ MAXN ] ;
struct node {
ll sm ;
int cnt ;
node *pl , *pr ;
node ( ) { sm = cnt = 0 ; pl = pr = NULL ; }
node ( node *_pl , node *_pr ) {
pl = _pl ; pr = _pr ;
sm = 0 ; cnt = 0 ;
if ( pl != NULL ) {
sm += pl->sm ;
cnt += pl->cnt ;
}
if ( pr != NULL ) {
sm += pr->sm ;
cnt += pr->cnt ;
}
}
};
node* root[ MAXN ] ;
node* init ( int l , int r ) {
if ( l == r ) { return new node ( ) ; }
int mid = ( l + r ) / 2 ;
node *ret = new node ( init ( l , mid ) , init ( mid + 1 , r ) ) ;
return ret ;
}
node* update ( node *w , int l , int r , int pos , int add ) {
if ( l == r ) {
node *ret = new node ( ) ;
++ ret->cnt ;
ret->sm += add ;
return ret ;
}
int mid = ( l + r ) / 2 ;
if ( pos <= mid ) {
return new node ( update ( w->pl , l , mid , pos , add ) , w->pr ) ;
}
else {
return new node ( w->pl , update ( w->pr , mid + 1 , r , pos , add ) ) ;
}
}
pair < ll , int > query ( node *st , node *en , int l , int r , int lft ) {
if ( lft == 0 ) { return { 0 , 0 } ; }
if ( en->cnt - st->cnt <= lft ) {
return { en->sm - st->sm , en->cnt - st->cnt } ;
}
int mid = ( l + r ) / 2 ;
pair < ll , int > ret1 = query ( st->pr , en->pr , mid + 1 , r , lft ) ;
pair < ll , int > ret2 = query ( st->pl , en->pl , l , mid , lft - ret1.second ) ;
return { ret1.first + ret2.first , ret1.second + ret2.second } ;
}
ll ans[ MAXN ] ;
ll calc ( int x , int y ) {
if ( y - x - 1 < k - 2 ) { return -inf ; }
ll ret = 2 * ( a[ x ].second - a[ y ].second ) ;
ret += a[ x ].first + a[ y ].first ;
pair < ll , int > hh = query ( root[ x ] , root[ y - 1 ] , 1 , n , k - 2 ) ;
ret += hh.first ;
return ret ;
}
void f ( int l , int r , int st , int en ) {
if ( l > r ) { return ; }
int mid = ( l + r ) / 2 ;
int wh = -1 ;
for ( int i = min ( mid , st ) ; i <= en ; ++ i ) {
ll cand = calc ( mid , i ) ;
if ( ans[ mid ] < cand ) {
ans[ mid ] = cand ;
wh = i ;
}
}
if ( l < mid ) {
f ( l , mid - 1 , st , wh ) ;
}
if ( mid < r ) {
f ( mid + 1 , r , wh , en ) ;
}
}
void input ( ) {
cin >> n >> k ;
for ( int i = 1 ; i <= n ; ++ i ) {
cin >> a[ i ].first >> a[ i ].second ;
}
auto cmp = [ & ] ( pair < int , int > p1 , pair < int , int > p2 ) {
return ( p1.second < p2.second ) ;
};
sort ( a + 1 , a + n + 1 , cmp ) ;
for ( int i = 1 ; i <= n ; ++ i ) {
srt[ i ] = { a[ i ].first , i } ;
}
sort ( srt + 1 , srt + n + 1 ) ;
for ( int i = 1 ; i <= n ; ++ i ) {
ord[ srt[ i ].second ] = i ;
}
}
void solve ( ) {
root[ 0 ] = init ( 1 , n ) ;
for ( int i = 1 ; i <= n ; ++ i ) {
root[ i ] = update ( root[ i - 1 ] , 1 , n , ord[ i ] , a[ i ].first ) ;
}
for ( int i = 1 ; i <= n - k + 1 ; ++ i ) {
ans[ i ] = -inf ;
}
f ( 1 , n , 1 , n ) ;
ll ret = -inf ;
for ( int i = 1 ; i <= n - k + 1 ; ++ i ) {
ret = max ( ret , ans[ i ] ) ;
}
cout << ret << "\n" ;
}
int main ( ) {
ios_base :: sync_with_stdio ( false ) ;
cin.tie ( NULL ) ;
int t = 1 ;
// cin >> t ;
while ( t -- ) {
input ( ) ;
solve ( ) ;
}
return 0 ;
}
