#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 2e5 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;
vector<int> a;
vector <int> val[maxN * 4];
vector <int> sum[maxN * 4];
int node_cnt = 1;
struct TNode
{
int l, r;
int lp, rp;
TNode()
{
l = r = lp = rp = 0;
}
TNode(int _l, int _r)
{
l = _l;
r = _r;
}
};
TNode wt[maxN * 4];
void build(int id, auto i, auto j, int l, int r)
{
wt[id].l = l;
wt[id].r = r;
if (l == r)
{
return;
}
val[id].pb(0);
sum[id].pb(0);
int mid = (l + r - (l + r < 0)) / 2;
int _max = l;
int _min = r;
for(auto it = i; it != j; ++it)
{
val[id].pb(val[id].back() + (*it <= mid));
sum[id].pb(sum[id].back() + *it * (*it <= mid));
if (*it <= mid) _max = max(_max, *it);
else _min = min(_min, *it);
}
auto p = stable_partition(i, j,[=](const auto &w)
{
return w <= mid;
});
wt[id].lp = ++node_cnt;
wt[id].rp = ++node_cnt;
build(wt[id].lp, i, p, l, _max);
build(wt[id].rp, p, j, _min, r);
}
ll get(int k, int i, int j)
{
if (k == 0) return 0;
--i;
ll res = 0;
int id = 1;
int l = wt[id].l, r = wt[id].r;
while (l < r)
{
int mid = (l + r) / 2;
if (k <= val[id][j] - val[id][i])
{
i = val[id][i];
j = val[id][j];
id = wt[id].lp;
}
else
{
res += sum[id][j] - sum[id][i];
k -= val[id][j] - val[id][i];
i -= val[id][i];
j -= val[id][j];
id = wt[id].rp;
}
l = wt[id].l, r = wt[id].r;
}
res += k * l;
return res;
}
int n, m;
pair<int, int> cake[maxN];
int f[maxN];
void ReadInput()
{
cin >> n >> m;
for(int i=1; i<=n; i++) cin >> cake[i].fi >> cake[i].se;
}
void Solve()
{
sort(cake + 1, cake + n + 1, [](pair<int, int> p, pair<int, int> q)
{
return p.se < q.se;
});
a.resize(n + 1);
for(int i=1; i<=n; i++) a[i] = -cake[i].fi;
build(1, a.begin() + 1, a.end(), *min_element(a.begin() + 1, a.end()), *max_element(a.begin() + 1, a.end()));
for(int i=m; i<=n; i++)
for(int j=i-m+1; j>=1; j--)
{
f[i] = max(f[i], -get(m, j, i) - (cake[i].se - cake[j].se) * 2);
// cout << f[j - 1] + cake[i].fi + cake[j].fi + -get(m - 2, j + 1, i - 1) - (cake[i].se - cake[j].se) * 2;return;
}
cout << *max_element(f + m, f + n + 1);
}
int32_t main()
{
//freopen("x.inp", "r", stdin);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
ReadInput();
Solve();
}
