#include <bits/stdc++.h>
#define long long long
#define pii pair<int, int>
#define x first
#define y second
using namespace std;
const int N = 2e5+5;
vector<int> coord;
int get(int x) { return lower_bound(coord.begin(), coord.end(), x) - coord.begin() + 1; }
struct node {
long sum, cnt;
node *l, *r;
node(long sum, long cnt, node *l, node *r) : sum(sum), cnt(cnt), l(l), r(r) { }
};
node* newleaf(long sum, long cnt) {
return new node(sum, cnt, nullptr, nullptr);
}
node* newpar(node *l, node *r) {
return new node(l->sum + r->sum, l->cnt + r->cnt, l, r);
}
node* build(int l = 1, int r = coord.size()) {
if(l == r) return newleaf(0, 0);
int mid = (l + r) >> 1;
return newpar(build(l, mid), build(mid + 1, r));
}
node* update(long sum, int x, node *p, int l = 1, int r = coord.size()) {
if(l == r) return newleaf(p->sum + sum, p->cnt + 1);
int mid = (l + r) >> 1;
if(x <= mid) return newpar(update(sum, x, p->l, l, mid), p->r);
else return newpar(p->l, update(sum, x, p->r, mid + 1, r));
}
long query(int k, node *pa, node *pb, int l = 1, int r = coord.size()) {
if(!k) return 0;
if(l == r) return pb->sum - pa->sum;
long sum_r = pb->r->sum - pa->r->sum, cnt_r = pb->r->cnt - pa->r->cnt;
int mid = (l + r) >> 1;
if(cnt_r >= k) return query(k, pa->r, pb->r, mid + 1, r);
else return sum_r + query(k - cnt_r, pa->l, pb->l, l, mid);
}
int n, m;
node* t[N];
pii v[N];
long ans[N];
void solve(int l, int r, int optl, int optr) {
if(l > r) return;
int mid = (l + r) >> 1, idx = optl;
for(int i = max(mid + m - 1, optl); i <= optr; i++) {
long now = query(m - 2, t[mid], t[i - 1]) + v[i].x + v[mid].x - 2ll * (v[i].y - v[mid].y);
if(now > ans[mid]) ans[mid] = now, idx = i;
}
solve(l, mid - 1, optl, idx), solve(mid + 1, r, idx, optr);
}
int main() {
fill_n(ans, N, -2e18);
scanf("%d %d", &n, &m);
for(int i = 1; i <= n; i++) {
scanf("%d %d", &v[i].x, &v[i].y);
coord.emplace_back(v[i].x);
}
sort(v + 1, v + n + 1, [&](const pii &a, const pii &b) {
return a.y < b.y;
});
sort(coord.begin(), coord.end());
coord.resize(unique(coord.begin(), coord.end()) - coord.begin());
t[0] = build();
for(int i = 1; i <= n; i++) t[i] = update(v[i].x, get(v[i].x), t[i-1]);
solve(1, n - m + 1, 1, n);
long ret = -2e18;
for(int i = 1; i <= n; i++) ret = max(ret, ans[i]);
printf("%lld\n", ret);
return 0;
}
