import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; public class Main { public static void main(String[] args) { int N = nextInt(); int[] x = new int[N]; int[] y = new int[N]; for (int i = 0; i < N; i++) { x[i] = nextInt(); y[i] = nextInt(); } Kruscal g = new Kruscal(N); for (int i = 0; i < N; i++) { for (int j = 0; j < i; j++) { long dx = x[i] - x[j]; long dy = y[i] - y[j]; long distSq = dx * dx + dy * dy; long d = (long) Math.sqrt(distSq); while (distSq > d * d) { d += 10; } // long d = (sqrtCeil(distSq) + 9) / 10 * 10; g.addBidirectionalEdge(i, j, (int) d); } } System.out.println(g.minCost()); } static long sqrtCeil(long n) { long l = 0; long r = 2000000000; while (l + 1 < r) { // (l+r)/2を超えない整数 long c = (l + r) >>> 1; if (c * c >= n) { r = c; } else { l = c; } } return r; } static int nextInt() { int c; try { c = System.in.read(); while (c != '-' && (c < '0' || c > '9')) c = System.in.read(); if (c == '-') return -nextInt(); int res = 0; while (c >= '0' && c <= '9') { res = res * 10 + c - '0'; c = System.in.read(); } return res; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return -1; } } class Kruscal { int n; ArrayList graph = new ArrayList(); public Kruscal(int n) { this.n = n; } public void addBidirectionalEdge(int u, int v, int cost) { // System.out.println(u + "," + v + "," + cost); graph.add(new Edge(cost, u, v)); } public int minCost() { Collections.sort(graph); // System.out.println(graph); UnionFind uf = new UnionFind(n); int ans = 0; int connected = 1; for (int i = 0; i < graph.size(); i++) { Edge e = graph.get(i); if (!uf.isConnected(e.from, e.to)) { uf.union(e.from, e.to); connected++; ans = Math.max(ans, e.cost); if (connected == n) { break; } } if (uf.isConnected(0, n - 1)) { return ans; } } return ans; } static class Edge implements Comparable { int cost; int from; int to; public Edge(int cost, int from, int to) { this.cost = cost; this.from = from; this.to = to; } @Override public int compareTo(Edge o) { if (this.cost == o.cost) { return 0; } else if (this.cost > o.cost) { return 1; } else { return -1; } } public String toString() { return this.cost + "," + this.from + "," + this.to; } } static class UnionFind { private int[] data; public UnionFind(int size) { data = new int[size]; Arrays.fill(data, -1); } public void union(int x, int y) { x = root(x); y = root(y); if (x != y) { if (data[y] < data[x]) { int tmp = y; y = x; x = tmp; } data[x] += data[y]; data[y] = x; } } public boolean isConnected(int x, int y) { return root(x) == root(y); } private int root(int x) { return data[x] < 0 ? x : (data[x] = root(data[x])); } public int size(int x) { return -data[root(x)]; } public String toString() { return Arrays.toString(data); } } }