import java.util.*;
import java.math.*;

public class Main {
    static int[] base;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] xArr = new int[n];
        int[] yArr = new int[n];
        for (int i = 0; i < n; i++) {
            xArr[i] = sc.nextInt();
            yArr[i] = sc.nextInt();
        }
        long[][] sizes = new long[n][n];
        for (int i = 0; i < n - 1; i++) {
            for (int j = i + 1; j < n; j++) {
                sizes[i][j] = getSize(xArr[i], yArr[i], xArr[j], yArr[j]);
            }
        }
        long left = 0;
        long right = (int)(Math.sqrt(sizes[0][n - 1]) / 10 + 1);
        while (right - left > 1) {
            long m = (left + right) / 2;
            UnionFindTree uft = new UnionFindTree(n);
            for (int i = 0; i < n - 1; i++) {
                for (int j = i + 1; j < n; j++) {
                    if ((m * 10) * (m * 10) >= sizes[i][j]) {
                        uft.unite(i, j);
                    }
                }
            }
            if (uft.same()) {
                right = m;
            } else {
               left = m;
            }
        }
        System.out.println(right * 10);
    }
    
    static class UnionFindTree {
        int[] parents;
        
        public UnionFindTree(int size) {
            parents = new int[size];
            for (int i = 0; i < size; i++) {
                parents[i] = i;
            }
        }
        
        public int find(int x) {
            if (parents[x] == x) {
                return x;
            } else {
                return parents[x] = find(parents[x]);
            }
        }
        
        public void unite(int x, int y) {
            int xx = find(x);
            int yy = find(y);
            if (xx == yy) {
                return;
            }
            parents[xx] = yy;
        }
        
        public boolean same() {
            return find(0) == find(parents.length - 1);
        }
    }
    
    static long getSize(long x1, long y1, long x2, long y2) {
        return (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
    }
}