#include<bits/stdc++.h>
using namespace std;
#ifndef BADGNU
#pragma GCC target("sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#endif
#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ll long long
#define int ll
#define ld long double
#define y1 cheza
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<class T> using ordered_multiset = tree<T,null_type,less_equal<T>,rb_tree_tag,tree_order_statistics_node_update>;
const int N=3e5+100;
const int M=5001;
const int B=447;
const int mod=998244353;
const ll INF=1e18;
const int dx[]={1,-1,0,0};
const int dy[]={0,0,1,-1};
const double eps=1e-6;
int n,k;
pair<int,int>a[N];
int rv[N];
int ans=-INF;
int _l=1;
int _r=0;
pair<int,int> t[N*4];
pair<int,int> operator+(const pair<int,int>&x,const pair<int,int>&y){
pair<int,int>res;
res.first=(x.first+y.first);
res.second=(x.second+y.second);
return res;
}
void upd(int v,int tl,int tr,int l,int x){
if(tl==tr){
t[v].first+=x;
t[v].second+=(x*rv[tl]);
return;
}
int mid=(tl+tr)>>1ll;
if(l<=mid){
upd(v*2,tl,mid,l,x);
}
else{
upd(v*2+1,mid+1,tr,l,x);
}
t[v]=(t[v*2]+t[v*2+1]);
}
pair<int,int> get(int v,int tl,int tr,int x){
if(t[v].first<=x)return t[v];
if(tl==tr){
return {x,rv[tl]*x};
}
int mid=(tl+tr)>>1ll;
auto res=get(v*2+1,mid+1,tr,x);
x-=res.second;
if(x>0){
res=(res+get(v*2,tl,mid,x));
}
return res;
}
int calc(int l,int r){
for(;_r<r;_r++)upd(1,1,n,a[_r+1].second,1);
for(;_l>l;_l--)upd(1,1,n,a[_l-1].second,1);
for(;_l<l;_l++)upd(1,1,n,a[_l].second,-1);
for(;_r>r;_r--)upd(1,1,n,a[_r].second,-1);
int res=get(1,1,n,k).second-(a[r].first-a[l].first)*2ll;
return res;
}
void solve(int l,int r,int tl,int tr){
if(l>r)return;
int mid=(l+r)>>1ll;
pair<int,int>best={-INF,-INF};
for(int i=max(mid+k-1,tl);i<=tr;i++){
best=max(best,make_pair(calc(mid,i),i));
}
ans=max(ans,best.first);
solve(l,mid-1,tl,best.second);
solve(mid+1,r,best.second,tr);
}
void test(){
cin>>n>>k;
for(int i=1;i<=n;i++){
cin>>a[i].first>>a[i].second;
swap(a[i].first,a[i].second);
}
map<int,int>mem;
for(int i=1;i<=n;i++){
mem[a[i].second]=0;
}
int tin=0;
for(auto &i:mem){
i.second=++tin;
rv[i.second]=i.first;
}
for(int i=1;i<=n;i++){
a[i].second=mem[a[i].second];
}
sort(a+1,a+n+1);
solve(1,n-k+1,1,n);
cout<<ans<<'\n';
}
/*
*/
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// cout.tie(nullptr);
int t2=1;
// cin>>t2;
for(int i=1;i<=t2;i++){
test();
}
}
