//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
//#define int long long
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(lmao) lmao.begin(), lmao.end()
using namespace std;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tp;
const int N = 1e6 + 5;
//const int mod = 1e9 + 7;
const ll oo = 5e18;
ll n, m, k, val[N], f[5][N], pre, nx, p[N];
void sol(int l,int r,int pl,int pr){
if(l > r) return;
int mid = (l + r) / 2;
f[nx][mid] = oo;
int pos = pl;
for(int i = pl; i <= min(mid - 1, pr); i ++){
ll w = 1ll * (p[mid] - p[i + 1] + val[p[i + 1]]) * (p[mid] - p[i + 1] + val[p[i + 1]])
+ f[pre][i] - 1ll * max(0ll, val[p[i + 1]] - p[i + 1] + p[i]) * max(0ll, val[p[i + 1]] - p[i + 1] + p[i]);
// cout << " " << mid << " " << i << " " << pre << " " << f[pre][i] << " " << w << " ee\n";
if(w < f[nx][mid]){
f[nx][mid] = w;
pos = i;
}
}
sol(l, mid - 1, pl, pos);
sol(mid + 1, r, pos, pr);
}
ll take_photos(int _n,int _m,int _k,vector<int> R,vector<int> C){
n = _n, m = _m, k = _k;
deque<int> sk;
for(int i = 0; i < n; i ++){
ll r = ++R[i], c = ++C[i];
if(r <= c) val[c] = max(val[c], c - r + 1);
else val[r] = max(val[r], r - c + 1);
}
for(int i = 1; i <= m; i ++){
if(!val[i]) continue;
// cout << i << " " << val[i] << " u\n";
while(!sk.empty() && i - val[i] + 1 <= sk.front() - val[sk.front()] + 1) sk.pop_front();
sk.push_front(i);
}
vector<pii> vr;
int t = 0;
while(!sk.empty()){
p[++t] = sk.back();
sk.pop_back();
}
n = t;
if(n <= k){
ll ans = 1ll * val[p[1]] * val[p[1]];
for(int i = 2; i <= n; i ++){
ans += 1ll * val[p[i]] * val[p[i]] - 1ll * max(0ll, val[p[i]] - p[i] + p[i - 1]) * max(0ll, val[p[i]] - p[i] + p[i - 1]);
}
return ans;
}
nx = 1, pre = 0;
// for(int i = 1; i <= n; i ++){
// cout << p[i] << " " << val[p[i]] << " t\n";
// }
for(int i = 1; i <= n; i ++) f[0][i] = 1ll * (p[i] - p[1] + val[p[1]]) * (p[i] - p[1] + val[p[1]]);
// for(int i = 1; i <= n; i ++) cout << f[0][i] << " ";
// cout << "\n";
for(int j = 2; j <= k; j ++){
sol(j, n, j - 1, n);
// cout << j << " l\n";
// for(int i = j; i <= n; i ++) cout << f[nx][i] << " ";
// cout << "\n";
swap(pre, nx);
}
// cerr << f[pre][n] << "\n";
return f[pre][n];
}
//#define lpv
#ifdef lpv
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define task "v"
if(fopen(task ".inp","r")){
freopen(task ".inp","r",stdin);
freopen(task ".out","w",stdout);
}
int n, m, k; cin >> n >> m >> k;
vector<int> r(n), c(n);
for (int i = 0; i < n; ++i) cin >> r[i] >> c[i];
cout << take_photos(n, m, k, r, c) << "\n";
}
#endif // lpv
