#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2")
#define setp(x) cout<<fixed<<setprecision(x)
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define forn(i,a,b) for(int i=(a);i<(b);i++)
#define fore(i,a,b) for(int i=(a);i<=(b);i++)
#define pb push_back
#define F first
#define S second
#define fbo find_by_order
#define ook order_of_key
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
//template<typename T>
//using pbds = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
void SD(int t=0){ cout<<"PASSED "<<t<<endl; }
template<typename T> void amax(T &a, T b){ a=max(a,b); }
template<typename T> void amin(T &a, T b){ a=min(a,b); }
struct Hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }
    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

const ll INF = ll(1e18);
const int MOD = 998244353;
const bool DEBUG = 0;
const int MAXN = 100005;
const int LG = 21;
const int MAXA = 256;

ll sq(ll x) { return x * x; }

int main()
{
    cin.tie(0)->sync_with_stdio(0);

    ll n,K; cin>>n>>K;
    ll cnt[MAXA + 1]{};
    forn(i,0,n)
    {
        ll r,c; cin>>r>>c; r++;
        cnt[r] += c;
    }

    ll cost[MAXA + 1][MAXA + 1]{};
    fore(i,0,MAXA)
    {
        ll sum = 0;
        fore(j, i + 1, MAXA)
        {
            sum += cnt[j] * sq(j - i);
            cost[i][j] = sum;
        }
        sum = 0;
        for (int j = i - 1; j >= 0; j--)
        {
            sum += cnt[j] * sq(j - i);
            cost[i][j] = sum;
        }
    }

    ll cost2[MAXA + 1][MAXA + 1]{};
    fore(i,0,MAXA) cost2[0][i] = cost[i][0];
    fore(k,1,MAXA) fore(i,k+1,MAXA)
    {
        ll minc = INF;
        for (int l = k; l <= i; l++)
        {
            minc = min(minc, cost[k][l] + cost[i][l + 1]);
        }
        cost2[k][i] = minc;
    }

    ll dp[MAXA + 1][K + 1];
    fore(i,0,MAXA) fore(j,0,K) dp[i][j] = INF;
    dp[0][0] = 0;
    fore(i,0,MAXA) fore(j,1,K)
    {
        ll& cur = dp[i][j];
        forn(k,0,i)
        {
            cur = min(cur, dp[k][j - 1] + cost2[k][i]);
        }
    }
    ll ans = INF;
    fore(i,0,MAXA)
    {
        amin(ans, dp[i][K] + cost[i][MAXA]);
    }
    cout << ans << '\n';

    return 0;
}