#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=0;
int _r=-1;
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;
}
template<int SZ> struct Seg {
pair<int,int> sum[2*SZ];
void upd(int pos, int val, int ind = 1, int L = 0, int R = SZ-1) {
if (L == R) {
sum[ind] = sum[ind]+make_pair(val*rv[pos],val);
return;
}
int M = (L+R)/2;
if (pos <= M) upd(pos,val,2*ind,L,M);
else upd(pos,val,2*ind+1,M+1,R);
sum[ind] = sum[2*ind]+sum[2*ind+1];
}
pair<int,int> query(int des, int ind = 1, int L = 0, int R = SZ-1) { // get M best
if (sum[ind].second <= des) return sum[ind];
if (L == R) {
auto a = sum[ind];
a.first /= a.second; a.second = des; a.first *= a.second;
return a;
}
int M = (L+R)/2;
auto a = query(des,2*ind+1,M+1,R);
des -= a.second;
if (des > 0) {
a = a+query(des,2*ind,L,M);
}
return a;
}
};
Seg<1<<18> S;
ll calc(int l, int r) {
while (_l > l) S.upd(a[--_l].second,1);
while (_r < r) S.upd(a[++_r].second,1);
while (_l < l) S.upd(a[_l++].second,-1);
while (_r > r) S.upd(a[_r--].second,-1);
ll ret = -2*(a[r].first-a[l].first);
ret += S.query(k).first;
return ret;
}
void solve(int l,int r,int tl,int tr){
if(l>r)return;
int mid=(l+r)>>1ll;
pair<int,int>best={-INF,tr};
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=-1;
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+1,0,n-1);
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();
}
}
