#include"bits/stdc++.h" //#include using namespace std; #define print(x) cout< PI; typedef pair V; const ll mod = 10000000000; //union-find木実装 int par[100002]; int ran[100002]; //初期化 void init(int n) { rep(i, 0, n) { par[i] = i; ran[i] = 0; } } //木の根を求める int find(int x) { if (par[x] == x) { return x; } else { return par[x] = find(par[x]); } } //xとyの属する集合を併合 void unite(int x, int y) { x = find(x); y = find(y); if (x == y) return; if (ran[x] < ran[y]) { par[x] = y; } else { par[y] = x; if (ran[x] == ran[y])ran[x]++; } } //xとyが同じ集合かどうか bool same(int x, int y) { return find(x) == find(y); } int main() { int n; double x[1002], y[1002]; double ans = 0; map eg; cin >> n; REP(i, n)cin >> x[i] >> y[i]; init(n); REP(i, n)rep(j, i + 1, n) { eg.insert(make_pair(sqrt(pow(x[i] - x[j], 2.0) + pow(y[i] - y[j], 2.0)), make_pair(i, j)));} for (auto itr = eg.begin(); itr != eg.end(); ++itr) { PI e = itr->second; if (!same(e.first, e.second)) { unite(e.first, e.second); double d = itr->first; ans = max(ans, d); } if (same(0, n - 1))break; } while ((int)ans % 10 != 0) { ans += 1; } print((int)ans); return 0; }