#include <bits/stdc++.h>
#define ll long long
#define ldb long double
#define endl '\n'
#define For(i,l,r) for(int i=l;i<=r;i++)
#define ForD(i,r,l) for(int i=r;i>=l;i--)
#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
#define sz(x) (signed)x.size()
#define unq(x) x.resize(unique(all(x))-x.begin())
#define F "TASK"
#define fio freopen(F".INP","r",stdin);freopen(F".OUT","w",stdout);
#ifdef NCGM
#include"debug.h"
#else
#define debug(...) "fr";
#endif
using namespace std;
const int N=2e5+3;
int n,m,pf[N],siz=0;
bool ski[N];
pair<int,int> a[N];
ll sm=0,ans[N];
vector<int> big;
void update(int x,int y) {
if (x==0) return;
siz+=y;
while(x<=n) {
pf[x]+=y;
x+=x&(-x);
}
}
int query(int x) {
int ans=0;
while(x>0) {
ans+=pf[x];
x-=x&(-x);
}
return ans;
}
int find_n(int x) {
int idx=0,cur=0;
ForD(i,17,0)
if (idx+(1<<i)<=n && cur+pf[idx+(1<<i)]<x) {
idx+=1<<i;
cur+=pf[idx];
}
return idx+1;
}
void add(int x,int idx) {
if (ski[idx]) return;
ski[idx]=1;
int tmp=siz-query(x-1);
if (siz<m || tmp<m) {
sm+=big[x-1];
if (siz>=m) {
int idx=find_n(siz-m+1);
sm-=big[idx-1];
}
}
update(x,1);
}
void rem(int x,int idx) {
if (!ski[idx]) return;
ski[idx]=0;
int tmp=siz-query(x-1);
if (tmp<=m) {
sm-=big[x-1];
if (siz>m) {
int huhu=find_n(siz-m);
sm+=big[huhu-1];
}
}
update(x,-1);
}
void solve(int l,int r,int lo,int hi) {
if (l>r) return;
int mid=l+r>>1;
For(i,mid,min(r,lo-1)) add(a[i].ff,i);
int opt=-1;
ans[mid]=-1e18;
For(i,max(mid,lo),hi) {
add(a[i].ff,i);
ll dis=2LL*(a[i].ss-a[mid].ss);
if (siz>=m && ans[mid]<sm-dis) {
opt=i;
ans[mid]=sm-dis;
}
}
// debug(l,r,lo,hi,mid,opt);
// cout << mid << " " << lo << " " << hi << endl;
// For(i,1,n) cout << ski[i] << " ";
// cout << endl;
// debug(mid,opt);
For(i,max(mid,lo),hi) rem(a[i].ff,i);
solve(l,mid-1,lo,opt);
For(i,mid,min(r,lo-1)) rem(a[i].ff,i);
For(i,max(r+1,lo),opt-1) add(a[i].ff,i);
solve(mid+1,r,opt,hi);
For(i,max(r+1,lo),opt-1) rem(a[i].ff,i);
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m;
For(i,1,n) {
cin >> a[i].ff >> a[i].ss;
big.pb(a[i].ff);
}
sort(all(big));
unq(big);
For(i,1,n) a[i].ff=(lower_bound(all(big),a[i].ff)-big.begin())+1;
sort(a+1,a+1+n,[=](const pair<int,int> A,const pair<int,int> B){
return make_pair(A.ss,A.ff)<make_pair(B.ss,B.ff);
});
solve(1,n-m+1,1,n);
ll res=*max_element(ans+1,ans+n-m+2);
cout << res;
return 0;
}
