#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define vint vector<int>
using namespace std;
#ifndef x
// #include ".h"
#else
#endif
int n, k;
vector<ll> l, r;
ll p2(ll x) {
return x * x;
}
ll I(int i) {
if(r[i] < l[i + 1]) return 0;
return p2(r[i] - l[i + 1] + 1);
}
ll P(array<ll, 3> p, ll x) {
return p[0] * x + p[1];
}
bool CW(array<ll, 2> a, array<ll, 2> b) {
return (a[0] * b[1] - b[0] * a[1] < 0);
}
bool CW(array<ll, 3> a, array<ll, 3> b, array<ll, 3> c) {
a[0] = b[0] - a[0];
a[1] = b[1] - a[1];
b[0] = c[0] - b[0];
b[1] = c[1] - b[1];
return CW({a[0], a[1]}, {b[0], b[1]});
}
array<ll, 2> dpsol(ll am) {
vector<array<ll, 2> > dp(n);
dp[0] = {p2(r[0] - l[0] + 1) + am, 1};
deque<array<ll, 3> > d;
int dg = 0;
for(int i = 0; i < n; ++i) {
// cout << i << " |\n";
if(i > 0) {
ll x = -r[i];
ll c = p2(r[i] + 1) + am;
// cout << "x, c: " << x << " " << c << endl;
if(0) {
while(dg < sz(d) - 1 && P(d[dg + 1], x) < P(d[dg], x)) dg += 1;
dp[i][0] = P(d[dg], x) + c;
dp[i][1] = d[dg][2] + 1;
} else {
dp[i][0] = 1e18;
for(int j = 0; j < sz(d); ++j) {
ll t = P(d[j], x) + c;
if(dp[i][0] > t) {
dp[i][0] = t;
dp[i][1] = d[j][2] + 1;
} else if(dp[i][0] == t) {
dp[i][1] = min(dp[i][1], d[j][2] + 1);
}
}
}
// cout << "a', b': " << d[dg][0] << " " << d[dg][1] << endl;
ll y = p2(r[i] - l[0] + 1) + am;
if(dp[i][0] >= y) {
dp[i][0] = y;
dp[i][1] = 1;
}
}
// cout << "dp: " << dp[i][0] - 0 * dp[i][1] * am << " " << dp[i][1] << endl;
if(i < n - 1) {
ll a = 2ll * l[i + 1];
ll b = dp[i][0] - I(i) - 2ll * l[i + 1];
b += p2(l[i + 1]);
// cout << "a, b: " << a << " " << b << endl;
array<ll, 3> x = {a, b, dp[i][1]};
if(0) {
while(sz(d) >= 2 && CW(d[sz(d) - 2], d[sz(d) - 1], x)) {
// cout << "popped: " << d.back()[0] << " " << d.back()[1] << endl;
d.pop_back();
}
}
d.push_back(x);
dg = min(dg, sz(d) - 1);
}
}
array<ll, 2> x = dp[n - 1];
x[0] -= x[1] * am;
return x;
}
ll dpsol_new_61() {
vector<vector<ll> > dp(n, vector<ll>(k + 1));
deque<array<ll, 3> > d[k + 1];
vector<int> dg(k + 1);
for(int i = 0; i < n; ++i) {
dp[i][1] = p2(r[i] - l[0] + 1);
for(int j = min(i, k - 1); j >= 0; --j) {
// cout << "i, j + 1: " << i << " " << j + 1 << "|\n";
if(j > 0) {
ll x = -r[i];
ll c = p2(r[i] + 1);
while(dg[j] < sz(d[j]) - 1 && P(d[j][dg[j] + 1], x) < P(d[j][dg[j]], x)) dg[j] += 1;
dp[i][j + 1] = P(d[j][dg[j]], x) + c;
}
// cout << "dp: " << dp[i][j + 1] << "\n";
///////////
if(i < n - 1) {
ll a = 2ll * l[i + 1];
ll b = dp[i][j + 1] - I(i) - 2ll * l[i + 1];
b += p2(l[i + 1]);
array<ll, 3> x = {a, b, 0};
while(sz(d[j + 1]) >= 2 && CW(d[j + 1][sz(d[j + 1]) - 2], d[j + 1][sz(d[j + 1]) - 1], x)) {
d[j + 1].pop_back();
}
d[j + 1].push_back(x);
dg[j + 1] = min(dg[j + 1], sz(d[j + 1]) - 1);
}
}
}
return dp[n - 1][min(k, n)];
}
ll take_photos(int N, int m, int K, vint R, vint C) {
n = N;
k = K;
vector<int> lg(m, m);
for(int i = 0; i < n; ++i) {
array<int, 2> x = {R[i], C[i]};
if(x[0] > x[1]) swap(x[0], x[1]);
lg[x[1]] = min(lg[x[1]], x[0]);
}
vector<array<int, 2> > v;
for(int i = 0; i < m; ++i) {
if(lg[i] == m) continue;
while(sz(v) && lg[i] <= v.back()[0]) {
v.pop_back();
}
v.push_back({lg[i], i});
}
n = sz(v);
l = r = vector<ll>(n);
for(int i = 0; i < n; ++i) {
l[i] = v[i][0];
r[i] = v[i][1];
}
ll al = 0, ar = 1ll * m * m;
// al = ar = 4;
while(al < ar) {
ll am = (al + ar) / 2;
if(dpsol(am)[1] > k) al = am + 1;
else ar = am;
}
array<ll, 2> x = dpsol(al);
// cout << x[1] << " " << al << endl;
return x[0];
///
// return dpsol_new_61();
}
#ifdef x
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout << take_photos(4, 4, 2, {0, 1, 2, 3}, {0, 1, 2, 3}) << endl;
// return 0;
cout << "----" << endl;
cout << take_photos(9, 9, 2, {0, 1, 2, 3, 4, 5, 6, 7, 8}, {0, 1, 2, 3, 4, 5, 6, 7, 8}) << endl;
cout << "----" << endl;
cout << take_photos(5, 5, 5, {0, 1, 2, 3, 4}, {0, 1, 2, 3, 4}) << endl;
cout << take_photos(5, 5, 4, {0, 1, 2, 3, 4}, {0, 1, 2, 3, 4}) << endl;
cout << take_photos(5, 5, 3, {0, 1, 2, 3, 4}, {0, 1, 2, 3, 4}) << endl;
cout << take_photos(5, 5, 2, {0, 1, 2, 3, 4}, {0, 1, 2, 3, 4}) << endl;
cout << take_photos(5, 5, 1, {0, 1, 2, 3, 4}, {0, 1, 2, 3, 4}) << endl;
cout << "----" << endl;
cout << take_photos(2, 2, 1, {0, 1}, {0, 1}) << endl;
cout << take_photos(2, 2, 2, {0, 1}, {0, 1}) << endl;
cout << take_photos(1, 2, 1, {0}, {1}) << endl;
cout << "----" << endl;
cout << take_photos(5, 7, 1, {0, 4, 4, 4, 4}, {3, 4, 6, 5, 6}) << endl;
cout << take_photos(5, 7, 2, {0, 4, 4, 4, 4}, {3, 4, 6, 5, 6}) << endl;
cout << take_photos(2, 6, 2, {1, 4}, {4, 1}) << endl;
return 0;
}
#endif
