#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e5 + 5;
ll cval[N];
struct segment_tree {
int size;
vector<ll> sum, cnt;
segment_tree() {}
segment_tree(int sz) {
size = sz;
sum.resize(4 * size);
cnt.resize(4 * size);
}
void upd(int t, int l, int r, int id, ll add) {
if (l + 1 == r) {
cnt[t] += add;
sum[t] += add * cval[id];
return;
}
int md = r + l >> 1;
if (md > id)
upd(t * 2 + 1, l, md, id, add);
else
upd(t * 2 + 2, md, r, id, add);
sum[t] = sum[t * 2 + 1] + sum[t * 2 + 2];
cnt[t] = cnt[t * 2 + 1] + cnt[t * 2 + 2];
}
void upd(int id, ll add) {
upd(0, 0, size, id, add);
}
ll get(int t, int l, int r, ll k) {
if (!k)
return 0;
if (l + 1 == r)
return cval[l] * min(k, cnt[t]);
int md = r + l >> 1;
if (cnt[t * 2 + 1] >= k)
return get(t * 2 + 1, l, md, k);
return sum[t * 2 + 1] + get(t * 2 + 2, md, r, k - cnt[t * 2 + 1]);
}
ll get(ll k) {
return get(0, 0, size, k);
}
};
segment_tree sgt(N);
int n, m;
pair<ll, ll> vc[N];
vector<ll> vf;
const ll inf = 1e15;
ll ans[N];
int L, R = -1;
void add(int id) {
sgt.upd(vc[id].first, 1);
}
void del(int id) {
sgt.upd(vc[id].first, -1);
}
void move(int l, int r) {
while (R < r) {
R++;
add(R);
}
while (L > l) {
L--;
add(L);
}
while (R > r) {
del(R);
R--;
}
while (L < l) {
del(L);
L++;
}
}
void dc(int l, int r, int optl, int optr) {
if (l > r)
return;
int md = l + r >> 1, opt = -1;
ll mx = -inf;
for (int p = max(optl, md + m - 1); p <= optr; ++p) {
move(md, p);
ll vl = sgt.get(m) - 2 * (vc[p].second - vc[md].second);
if (vl > mx) {
opt = p;
mx = vl;
}
}
assert(opt != -1);
ans[md] = mx;
dc(l, md - 1, optl, opt);
dc(md + 1, r, opt, optr);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m;
vf.resize(n);
for (int i = 0; i < n; ++i) {
cin >> vc[i].first >> vc[i].second;
vf[i] = vc[i].first;
}
sort(vc, vc + n, [&](pair<ll, ll> a, pair<ll, ll> b) { return a.second < b.second; });
sort(vf.begin(), vf.end());
vf.erase(unique(vf.begin(), vf.end()), vf.end());
sort(vf.rbegin(), vf.rend());
map<ll, ll> proper;
for (int i = 0; i < vf.size(); ++i) {
proper[vf[i]] = i;
cval[i] = vf[i];
}
for (int i = 0; i < n; ++i)
vc[i].first = proper[vc[i].first];
dc(0, n - m, 0, n - 1);
ll res = -inf;
for (int i = 0; i <= n - m; ++i)
res = max(res, ans[i]);
cout << res;
}
