#include <cstdio>
#include <algorithm>
#include <vector>
#include <cassert>
#include <iostream>
#include <map>
using namespace std;
typedef long long llong;
const llong linf = 1e13;
const int inf = 1e9;
llong sqr(int x) {
return 1ll * x * x;
}
bool convex(pair<llong, int> a, pair<llong, int> b, pair<llong, int> c) {
llong dx1 = b.first - a.first, dy1 = b.second - a.second;
llong dx2 = c.first - b.first, dy2 = c.second - b.second;
return dx1 * dy2 - dy1 * dx2 > 0;
}
long long take_photos(int n, int /* m */, int k, std::vector<int> row, std::vector<int> column) {
map<int, int> M;
for (int i = 0; i < n; i++) {
int x, y;
x = row[i];
y = column[i];
if (x < y)
swap(x, y);
if (!M.count(x))
M[x] = x;
M[x] = min(M[x], y);
}
vector<int> L, R;
for (auto pr : M) {
while (!L.empty() && L.back() >= pr.second)
L.pop_back(), R.pop_back();
R.push_back(pr.first);
L.push_back(pr.second);
}
n = L.size();
assert(is_sorted(R.begin(), R.end()));
assert(is_sorted(L.begin(), L.end()));
vector<llong> D;
vector<llong> nD;
D.assign(n + 1, linf);
D[0] = 0;
nD = D;
llong ans = linf;
vector<pair<llong, int>> st;
st.reserve(n);
for (int i = 0; i < k; i++) {
nD.assign(n + 1, linf);
st.clear();
nD[0] = 0;
int pt = 0;
for (int j = 0; j <= n; j++) {
if (j) {
int r2 = R[j - 1];
while (pt + 1 < (int)st.size()) {
llong scal1 = st[pt].first + (llong)st[pt].second * r2;
llong scal2 = st[pt + 1].first + (llong)st[pt + 1].second * r2;
if (scal1 > scal2)
pt++;
else
break;
}
llong val = st[pt].first + (llong)st[pt].second * r2;
llong cnst = (llong)r2 * r2;
nD[j] = cnst + val;
}
int r1 = j ? R[j - 1] : -1;
int l = L[j] - 1;
pair<llong, int> cur(D[j] + (llong)l * l - sqr(max(0, r1 - l)), -2 * l);
while (st.size() >= 2 && !convex(st[(int)st.size() - 2], st[(int)st.size() - 1], cur))
st.pop_back();
st.push_back(cur);
pt = min(pt, (int)st.size() - 1);
}
D.swap(nD);
ans = min(ans, D.back());
}
return ans;
}
// BEGIN CUT
/*
int main() {
int n, m, k;
scanf("%d %d %d", &n, &m, &k);
std::vector<int> r(n), c(n);
for (int i = 0; i < n; i++) {
scanf("%d %d", &r[i], &c[i]);
}
long long ans = take_photos(n, m, k, r, c);
// BEGIN SECRET
puts("098d134608c94f7413faac591054ee35");
// END SECRET
printf("%lld\n", ans);
return 0;
}
*/
// END CUT
