#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>

using namespace std;
 
struct UnionFind {
    vector<long long> par;
    vector<long long> siz;
 
    UnionFind(long long N) : par(N), siz(N) {
        for(long long i = 0; i < N; i++){
            par[i] = i;
            siz[i] = 1;
        }
    }
 
    long long root(long long x) {
        if (par[x] == x) return x;
        return par[x] = root(par[x]);
    }
 
    void unite(long long x, long long y) {
        long long rx = root(x);
        long long ry = root(y);
        if (rx == ry) return;
        par[rx] = ry;
        siz[ry] += siz[rx];
    }
 
    bool same(long long x, long long y) {
        long long rx = root(x);
        long long ry = root(y);
        return rx == ry;
    }
 
    long long size(long long x){
        return siz[root(x)];
    }
};

template<typename T> using pq = priority_queue<T, vector<T>, greater<T>>;

bool solve(long long n, long long m){
    return n*n*100 >= m;
}
 
int main(){
 
    long long N, c, ans, x, y, sq;
    cin >> N;
    pq<tuple<long long, long long, long long>> que;
    vector<long long> X(N), Y(N);
    for (int i=0; i<N; i++) cin >> X[i] >> Y[i];
    UnionFind tree(N+1);
 
    for (int i=0; i<N; i++){
        for (int j=i+1; j<N; j++){
            long long dx = X[i]-X[j], dy = Y[i]-Y[j];
            c = dx*dx + dy*dy;
            que.push({c, i, j});
        }
    }
 
    while(!que.empty()){
        tie(c, x, y) = que.top();
        que.pop();
        if (!tree.same(0, N-1)){
            ans = c;
            tree.unite(x, y);
        }
    }

    long long l=0, r=2e8;
    while(r-l>1){
        c = (l+r)/2;
        if(solve(c, ans)) r=c;
        else l=c;
    }

    cout << r*10 << endl;
 
    return 0;
}