#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define y0 y12
#define y1 y22
#define INF 987654321987654321
#define PI 3.141592653589793238462643383279502884
#define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
#define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
#define MEM0(a) memset((a),0,sizeof(a))
#define MEM_1(a) memset((a),-1,sizeof(a))
#define ALL(a) a.begin(),a.end()
#define SYNC ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;
typedef pair<ld, ld> Pd;
typedef vector<int> Vi;
typedef vector<ll> Vll;
typedef vector<db> Vd;
typedef vector<Pi> VPi;
typedef vector<Pll> VPll;
typedef vector<Pd> VPd;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef tuple<ll, ll, ll> LLL;
typedef vector<iii> Viii;
typedef vector<LLL> VLLL;
typedef complex<double> base;
const int MOD = 1000000007;
ll POW(ll a, ll b, ll MMM = MOD) { ll ret = 1; for (; b; b >>= 1, a = (a*a) % MMM)if (b & 1)ret = (ret*a) % MMM; return ret; }
int dx[] = { 0,1,0,-1,1,1,-1,-1 }, dy[] = { 1,0,-1,0,1,-1,1,-1 };
int ddx[] = { -1,-2,1,-2,2,-1,2,1 }, ddy[] = { -2,-1,-2,1,-1,2,1,2 };
ll d[505][505];
inline ll mul(ll x){return x*x;}
ll take_photos(int n,int m,int k,Vi r,Vi c){
VPi vv(n);
VPll p;
fup(i,0,n-1,1){
if(r[i]>c[i])swap(r[i],c[i]);
vv[i]=mp(r[i],c[i]);
}
sort(ALL(vv),[&](Pi p1,Pi p2){
if(p1.X!=p2.X)return p1.X<p2.X;
return p1.Y>p2.Y;
});
fup(i,0,n-1,1){
if(p.empty() || vv[i].Y>p.back().Y)p.pb(vv[i]);
}
n=p.size();
k=min(k,n);
fup(i,0,n-1,1){
d[i][1]=mul(p[i].Y-p[0].X+1);
}
fup(j,2,k,1){
fup(i,j-1,n-1,1){
d[i][j]=INF;
fup(ii,j-2,i-1,1){
ll t=d[ii][j-1]+mul(p[i].Y-p[ii+1].X+1);
if(p[ii+1].X<=p[ii].Y)t-=mul(p[ii].Y-p[ii+1].X+1);
d[i][j]=min(d[i][j],t);
}
}
}
return d[n-1][k];
}
/*int main(){
int n,m,k;
scanf("%d%d%d",&n,&m,&k);
Vi r(n),c(n);
fup(i,0,n-1,1)scanf("%d",&r[i]);
fup(i,0,n-1,1)scanf("%d",&c[i]);
printf("%lld\n",take_photos(n,m,k,r,c));
}*/
