#include <iostream>
#include <cmath>

using namespace std;

bool check[1000];
int Xs[1000], Ys[1000];
int N;

class Pos {
public:
    int x;
    int y;
    Pos(int x, int y) {
        this->x = x;
        this->y = y;
    }
    int distance(Pos pos) {
        return (x - pos.x) * (x - pos.x) + (y - pos.y) * (y - pos.y);
    }
};

void foo(int index, Pos now, Pos &pos1, Pos &pos2, Pos &pos3, Pos &pos4) {
    for (int i = 0; i < N; i++) {
        if (check[i]) {
            continue;
        }
        int x = Xs[i];
        int y = Ys[i];
        int distance = (x - now.x) * (x - now.x) + (y - now.y) * (y - now.y);
        if (distance <= 100) {
            check[i] = true;
            if(pos1.x > x && pos1.y > y) {
                pos1.x = x;
                pos1.y = y;
            }
            if(pos2.x > x && pos2.y < y) {
                pos2.x = x;
                pos2.y = y;
            }
            if(pos3.x < x && pos3.y > y) {
                pos3.x = x;
                pos3.y = y;
            }
            if(pos4.x < x && pos4.y < y) {
                pos4.x = x;
                pos4.y = y;
            }
            foo(i, Pos(x, y), pos1, pos2, pos3, pos4);
        }
    }
}

int main() {
    cin >> N;
    for (int i = 0; i < N; i++) {
        check[i] = false;
    }
    int ans = 0;
    for (int i = 0; i < N; i++) {
        cin >> Xs[i] >> Ys[i];
    }
    for (int i = 0; i < N; i++) {
        if (check[i]) {
            continue;
        }
        Pos pos1 = Pos(Xs[i], Ys[i]);
        Pos pos2 = Pos(Xs[i], Ys[i]);
        Pos pos3 = Pos(Xs[i], Ys[i]);
        Pos pos4 = Pos(Xs[i], Ys[i]);
        foo(i, Pos(Xs[i], Ys[i]), pos1, pos2, pos3, pos4);
        int a[] = {ans, pos1.distance(pos2), pos1.distance(pos3), pos1.distance(pos4), pos2.distance(pos3), pos2.distance(pos4), pos3.distance(pos4)};
        int tmp = 0;
        for (auto b : a) {
            if (b > tmp) {
                tmp = b;
            }
        }
        ans = tmp;
    }
    cout << sqrt(ans) + 2 << endl;
    return 0;
}