This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
//#pragma GCC optimize("")
using namespace std;
typedef long long ll;
const ll N = 2e5,logN = 32,maxa = 2e9;
const ll inf64 = 1ll*1e9*1e9;
const ll inf32 = 2e9;
struct numbers{
    ll v,c;
}v[N];
struct nod{
    ll cnt = 0,sum = 0,l = 0,r = 0;
};
nod seg[logN*N];
ll root[N];
ll n,k;
ll cnt2 = 1;
void upd(ll old,ll cur,ll val,ll l = 0,ll r = maxa){
    if(l == r){
        seg[cur].sum+=val;
        seg[cur].cnt++;
    }else{
        ll mij = (l + r)/2;
        if(val <= mij){
            seg[cur].r = seg[old].r;
            seg[cur].l = cnt2++;
            upd(seg[old].l,seg[cur].l,val,l,mij);
        }else{
            seg[cur].r = cnt2++;
            seg[cur].l = seg[old].l;
            upd(seg[old].r,seg[cur].r,val,mij + 1,r);
        }
        seg[cur].cnt = seg[seg[cur].l].cnt + seg[seg[cur].r].cnt;
        seg[cur].sum = seg[seg[cur].l].sum + seg[seg[cur].r].sum;
    }
}
ll get(ll old,ll cur,ll nr = k,ll l = 0,ll r = maxa){
    //cout<<old<<' '<<cur<<' '<<nr<<' '<<l<<' '<<r<<'\n';
    if(l == r){
        //cout<<nr*l<<'\n';
        return 1ll*nr*l;
    }else{
        ll mij = (l + r)/2;
        if(seg[seg[cur].r].cnt - seg[seg[old].r].cnt >= nr){
            return get(seg[old].r,seg[cur].r,nr,mij + 1,r);
        }else{
            //cout<<seg[seg[cur].r].sum - seg[seg[old].r].sum<<'\n';
            return seg[seg[cur].r].sum - seg[seg[old].r].sum + get(seg[old].l,seg[cur].l,nr - (seg[seg[cur].r].cnt - seg[seg[old].r].cnt),l,mij);
        }
    }
}
ll ans = -inf64;
void solve(ll l,ll r,ll l2,ll r2){
    if(l > r)return;
    ///haha shitty greedy wooo yeah
    ll score = -inf64,id = l2;
    ll mij = (l + r)/2,i;
    for(i = l2;i <= min(mij - k + 1,r2);i++){
        ll nr = get((i==0?0:root[i-1]),root[mij]);
        if(nr - v[mij].c + v[i].c > score){
            score = nr - v[mij].c + v[i].c;
            id = i;
        }
    }
    ans = max(ans,score);
    solve(l,mij - 1,l2,id);
    solve(mij + 1,r,id,r2);
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll i,j;
    cin>>n>>k;
    for(i = 0;i < n;i++){
        cin>>v[i].v>>v[i].c;
        v[i].c*=2;
    }
    sort(v,v + n,[&](numbers a,numbers b){
        return a.c < b.c;
    });
    for(i = 0;i < n;i++){
        root[i] = cnt2++;
        upd(i == 0?0:root[i-1],root[i],v[i].v);
    }
    solve(0,n - 1,0,n - 1);
    /*for(i = 0;i < n;i++){
        for(j = i + k - 1;j < n;j++){
            cout<<get(i == 0?0:root[i - 1],root[j])<<' '<<i<<' '<<j<<'\n';
        }
    }*/
    cout<<ans;
    return 0;
}
/**
5 3
2 1
4 2
6 4
8 8
10 16
**/
Compilation message (stderr)
cake3.cpp: In function 'int main()':
cake3.cpp:72:10: warning: unused variable 'j' [-Wunused-variable]
   72 |     ll i,j;
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