#include <iostream>
#include <vector>
#include <cmath>
#include <limits>

using namespace std;

long int foo(vector<pair<int, int>> r, int k) {
    long int sum = 0;
    for (auto ri : r) {
        sum += pow((ri.first - k),2) * ri.second;
    }
    return sum;
}

int main() {

    int N, K;
    cin >> N;
    cin >> K;
    vector<pair<int, int>> k = vector<pair<int, int>>();

    for (int i = 0; i < N; i++) {
        int first, second;
        cin >> first;
        cin >> second;
        k.push_back(make_pair(first, second));
    }

    int min = k[0].first;
    int max = k[k.size()-1].first;
    long int ret =  std::numeric_limits<int>::max();

    for (int i = min ; i <= max ; i++){
        long int res = foo(k, i);
        ret = res < ret ? res : ret;
    }
    cout << ret;
}