#include <bits/stdc++.h>
#define ld long double
#define endl "\n"
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb push_back
#define mp(a,b) make_pair(a,b)
#define ms(v,x) memset(v,x,sizeof(v))
#define all(v) v.begin(),v.end()
#define ff first
#define ss second
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define per(i, a, b) for(int i = b-1; i>=a ; i--)
#define trav(a, x) for(auto& a : x)
#define allin(a , x) for(auto a : x)
#define Unique(v) sort(all(v));v.erase(unique(all(v)),v.end());
#define sz(v) ((int)v.size())
using namespace std;
typedef vector<int> vi;
#define y1 abacaba
//#define left oooooopss
#define db(x) cerr << #x <<" == "<<x << endl;
#define db2(x,y) cerr<<#x <<" == "<<x<<", "<<#y<<" == "<<y<<endl;
#define db3(x,y,z) cerr << #x<<" == "<<x<<", "<<#y<<" == "<<y<<", "<<#z<<" == "<<z<<endl;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
std::mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down
inline ll mod(ll n, ll m ){ ll ret = n%m; if(ret < 0) ret += m; return ret; }
ll gcd(ll a, ll b){return (b == 0LL ? a : gcd(b, a%b));}
ll exp(ll b,ll e,ll m){
b%=m;
ll ans = 1;
for (; e; b = b * b % m, e /= 2)
if (e & 1) ans = ans * b % m;
return ans;
}
// debug:
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T){
cerr << ' ' << H;
dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr<<"(" << #__VA_ARGS__<<"):" , dbg_out(__VA_ARGS__) , cerr << endl
#else
#define dbg(...) 42
#endif
//
const int N = 200100;
pll a[N];// (V,C)
int pos[N];
struct node{
node *l,*r;
ll sum;
int qtd=0;
node(ll v = 0,int q=0){
l = r = NULL;
sum = v;
qtd = q;
}
};
typedef node* pnode;
pnode version[N];
void build(pnode no,int i,int j){
if(i == j){
return;
}
int mid = (i+j)/2;
no->l = new node();
no->r = new node();
build(no->l,i,mid);
build(no->r,mid+1,j);
}
void upd(pnode no,pnode old,int i,int j,int p,ll v){
if(i == j){
no->sum = old->sum + v;
no->qtd = old->qtd + 1;
return;
}
int mid = (i+j)/2;
if(p<=mid){
no->r = old->r;
if(no->l == NULL)no->l = new node();
upd(no->l,old->l,i,mid,p,v);
}else{
no->l = old->l;
if(no->r == NULL)no->r = new node();
upd(no->r,old->r,mid+1,j,p,v);
}
no->sum = no->l->sum + no->r->sum;
no->qtd = no->l->qtd + no->r->qtd;
}
pll query(pnode no,pnode old,int i,int j,int k){
if(i>j || k<=0 || no==NULL || old==NULL)return pll(0,0);
if(no->qtd - old->qtd <= k){
return pll(no->sum - old->sum,no->qtd - old->qtd);
}
int m = (i+j)/2;
auto a = query(no->r,old->r,m+1,j,k);
k-=a.ss;
auto b = query(no->l,old->l,i,m,k);
k-=b.ss;
return pll(a.ff + b.ff,a.ss + b.ss);
}
int T;
ll res = -1e18;
int n,M;
void solve(int l,int r,int optl,int optr){
if(l > r)return;
int m = (l+r)/2;
int optm=-1;
ll mx = -1e18;
for(int i = optl;i<=optr;i++){
if(m-i+1 < M)continue;
ll p1=-2ll * (a[m].ss - a[i].ss),p2 = a[m].ff + a[i].ff + query(version[m-1],version[i],1,T,M-2).ff;
ll cur = p1+p2;
if(cur > mx){
mx = cur;
optm = i;
}
}
res=max(res,mx);
if(optm==-1){
solve(m+1,r,optl,optr);
}
else{
solve(l,m-1,optl,optm);
solve(m+1,r,optm,optr);
}
}
int32_t main(){
fastio;
cin >> n >> M;
vi vals;
rep(i,1,n+1){
cin >> a[i].ff >> a[i].ss;
vals.pb(a[i].ff);
}
Unique(vals);
sort(a+1,a+1+n,[&](pll A,pll B){
return A.ss < B.ss;
});
T = sz(vals);
rep(i,1,n+1){
pos[i] = lower_bound(all(vals),a[i].ff) - vals.begin() + 1;
}
version[0] = new node();
build(version[0],1,T);
for(int i=1;i<=n;i++){
version[i] = new node();
upd(version[i],version[i-1],1,T,pos[i],a[i].ff);
}
solve(1,n,1,n);
cout << res << endl;
// math -> gcd it all
// Did u check N=1? Did you switch N,M?
}
