#include<bits/stdc++.h>
using namespace std;
#define jizz ios_base::sync_with_stdio(false);cin.tie(NULL);
typedef long long ll;
typedef pair<int,int> pii;
#define F first
#define S second
const ll MAXN=2E5+10, INF=1E18;
int n, m, pos[MAXN];
vector<int> cmp;
pii cake[MAXN];
ll ans[MAXN];
struct node{
ll cnt=0, val=0;
node* left=NULL;
node* right=NULL;
void pull(){
cnt=left->cnt+right->cnt;
val=left->val+right->val;
}
node(){};
node(node* a, node* b){
left=a, right=b;
pull();
}
};
node* root;
struct segment_tree{
int L=0, R=-1;
node* init(int l=0, int r=n-1){
if(l==r) return new node();
int mid=(l+r)/2;
return new node(init(l,mid),init(mid+1,r));
}
void modify(int p, int v, node* now=root, int l=0, int r=n-1){
if(l==r){
now->cnt+=(v>0?1:-1);
now->val+=v;
return;
}
int mid=(l+r)/2;
if(p<=mid) modify(p,v,now->left,l,mid);
else modify(p,v,now->right,mid+1,r);
now->pull();
}
ll query(int c=m, node* now=root, int l=0, int r=n-1){
if(R-L+1<m) return -INF;
if(c==0) return 0;
if(c==now->cnt) return now->val;
int mid=(l+r)/2;
if(now->right->cnt<=c){
return query(c-now->right->cnt,now->left,l,mid)+now->right->val;
} else{
return query(c,now->right,mid+1,r);
}
}
void update(int l, int r){
while(L>l){
modify(pos[L-1],cake[L-1].S);
L--;
}
while(R<r){
modify(pos[R+1],cake[R+1].S);
R++;
}
while(L<l){
modify(pos[L],-cake[L].S);
L++;
}
while(R>r){
modify(pos[R],-cake[R].S);
R--;
}
}
} sgt;
void solve(int l, int r, int ll, int rr){
if(l>r) return;
int mid=(l+r)/2, p=ll;
long long penalty=0, sum=0;
for(int i=ll;i<=rr;i++){
if(i<mid) continue;
penalty=2*(cake[i].F-cake[mid].F);
sgt.update(mid,i);
sum=sgt.query();
//cout<<mid<<" "<<i<<" "<<sum<<" "<<penalty<<"\n";
if(sum-penalty>ans[mid]){
ans[mid]=sum-penalty;
p=i;
}
}
solve(l,mid-1,ll,p);
solve(mid+1,r,p,rr);
}
int main(){ jizz
cin>>n>>m;
for(int i=0;i<n;i++){
cin>>cake[i].S>>cake[i].F;
cmp.push_back(cake[i].S);
}
sort(cake,cake+n);
sort(cmp.begin(),cmp.end());
cmp.erase(unique(cmp.begin(),cmp.end()),cmp.end());
for(int i=0;i<n;i++){
pos[i]=lower_bound(cmp.begin(),cmp.end(),cake[i].S)-cmp.begin();
}
for(int i=0;i<n;i++) ans[i]=-INF;
root=sgt.init();
solve(0,n-m,0,n-1);
ll ANS=-INF;
for(int i=0;i<n;i++) ANS=max(ANS,ans[i]);
cout<<ANS<<"\n";
return 0;
}
/*
8 4
112103441 501365808
659752417 137957977
86280801 257419447
902409188 565237611
965602301 689654312
104535476 646977261
945132881 114821749
198700181 915994879
*/
