//#include<i_am_noob_orz>
#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
using namespace std;
#define ll long long
#define int ll
#define ull unsigned long long
#define pii pair<int,int>
#define X first
#define Y second
#define mod ((ll)1e9+7)
#define pb push_back
#define mp make_pair
#define abs(x) ((x)>0?(x):(-(x)))
#define F(n) Fi(i,n)
#define Fi(i,n) Fl(i,0,n)
#define Fl(i,l,n) for(int i=l;i<n;i++)
#define memres(a) memset(a,0,sizeof(a))
#define all(a) a.begin(),a.end()
#define sz(a) ((int)a.size())
#define ceiling(a,b) (((a)+(b)-1)/(b))
#define endl '\n'
#define bit_count(x) __builtin_popcountll((x))
#define ykh mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define jimmy_is_kind false
//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> rbtree;
//#define LOCAL
#ifdef LOCAL
#define bug(...) cerr<<"#"<<__LINE__<<' '<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr<<x<<", "; _do(y...);}
#define IOS()
#else
#define IOS() ios_base::sync_with_stdio(0), cin.tie(0)
#define endl '\n'
#define bug(...)
#endif
int add(int a,int b){return(a+b>=mod?a+b-mod:a+b);}
int sub(int a,int b){return(a<b?a+mod-b:a-b);}
int po(int a,int b){
if(b==0)return 1;
if(b==1)return(a%mod);
int tem=po(a,b/2);
if(b&1)return(((tem*tem)%mod)*a)%mod;
else return(tem*tem)%mod;
}
int gcd(int a,int b){if(b==0)return a;return gcd(b,a%b);}
pii a[200010];
int n,m,ans=-1e18;
struct NODE{
multiset<int> ms1,ms2;
int l,r,v;
NODE():l(0),r(-1),v(0){}
inline void ins(int x){
//cout<<"in "<<x<<" "<<sz(ms1)<<endl;
if(sz(ms1)>=m){
if(x>*ms1.begin()){
v+=(x-*ms1.begin());
ms2.insert(*ms1.begin());
ms1.erase(ms1.begin());
ms1.insert(x);
}
else ms2.insert(x);
}
else ms1.insert(x),v+=x;
}
inline void rem(int x){
//cout<<"out "<<x<<endl;
if(ms1.count(x)){
//cout<<"cc"<<endl;
ms1.erase(ms1.find(x));
v-=x;
if(ms2.begin()!=ms2.end()){
//cout<<"ch"<<endl;
//cout<<"a "<<*ms2.rbegin()<<endl;
v+=*(ms2.rbegin());
ms1.insert(*ms2.rbegin());
ms2.erase(--ms2.end());
}
}
else {assert(ms2.count(x)||ms1.count(x));ms2.erase(ms2.find(x));}
}
}ms;
inline void change(NODE &ms,int l,int r){
//cout<<ms.l<<" "<<ms.r<<" "<<l<<" "<<r<<endl;
//cout<<ms.v<<endl;
while(r>ms.r)ms.ins(a[++ms.r].X);
while(l<ms.l)ms.ins(a[--ms.l].X);
while(r<ms.r)ms.rem(a[ms.r--].X);
//cout<<"a"<<endl;
while(l>ms.l)ms.rem(a[ms.l++].X);
//for(auto i:ms.ms1)cout<<i<<" ";
//cout<<endl;
//for(auto i:ms.ms2)cout<<i<<" ";
//cout<<endl;
}
bool cmp(pii a,pii b){return(a.Y==b.Y?a.X>b.X:a.Y<b.Y);}
inline void DAC(int l,int r,int dl,int dr){
if(l>r)return;
int s=0,mi=(l+r)/2,opt=-1e18,optp=-1;
//cout<<l<<" "<<r<<endl;
for(int i=dl;i<=mi-m+1&&i<=dr;i++){
change(ms,i,mi);
//cout<<i<<endl;
if(mi-i+1>=m&&ms.v-2*(a[mi].Y-a[i].Y)>opt)opt=ms.v-2*(a[mi].Y-a[i].Y),optp=i;
}
ans=max(ans,opt);
DAC(l,mi-1,dl,optp),DAC(mi+1,r,optp,dr);
return;
}
signed main(){
IOS();
cin>>n>>m;
F(n)cin>>a[i].X>>a[i].Y;
sort(a,a+n,cmp);
DAC(0,n-1,0,n-1);
cout<<ans<<endl;
return 0;
}
