#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long long lint;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const double inf = 1e12, pi = 3.14159265358979;

using point = pair<double, double>;
#define x first
#define y second

int N;
vector<tuple<int, int, int>> a;

double dist(point a, point b) {
    return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
}

double closest(vector<point>& v) {
    if (v.size() <= 1) return inf;

    int N = v.size();
    int K = N / 2;
    
    sort(v.begin(), v.end());

    vector<point> v1, v2;
    for (int i=0; i<K; i++) v1.push_back(v[i]);
    for (int i=K; i<N; i++) v2.push_back(v[i]);

    double ans = min(closest(v1), closest(v2));

    double xmid = v2[0].x;

    vector<point> v1p, v2p;
    for (auto [x, y] : v1) if (abs(xmid - x) <= ans) v1p.emplace_back(x, y);
    for (auto [x, y] : v2) if (abs(xmid - x) <= ans) v2p.emplace_back(x, y);

    v1 = v1p;
    v2 = v2p;

    sort(v1.begin(), v1.end(), [](point a, point b) { return a.y < b.y; });
    sort(v2.begin(), v2.end(), [](point a, point b) { return a.y < b.y; });

    double ans2 = inf;
    for (int i=0, l=0, r=0; i<v1.size(); i++) {
        while (l < v2.size() and v2[l].y < v1[i].y - ans) l++;
        while (r < v2.size() and v2[r].y <= v1[i].y + ans) r++;

        for (int j=l; j<r; j++) ans2 = min(ans2, dist(v1[i], v2[j]));
    }

    return min(ans, ans2);
}

int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    
    cin >> N;
    for (int i=0; i<N; i++) {
        int r, theta, t;
        cin >> r >> theta >> t;

        a.emplace_back(t, r, theta);
    }

    sort(a.begin(), a.end());

    multiset<int> rs;
    for (int i=0; i<N; i++) rs.insert(get<1>(a[i]));

    double ans = inf;

    for (int i=0; i<N; ) {
        int j = i;

        while (j<N and get<0>(a[i]) == get<0>(a[j])) j++;

        for (int k=i; k<j; k++) rs.erase(rs.lower_bound(get<1>(a[k])));

        for (int k=i; k<j; k++) {
            auto it = rs.lower_bound(get<1>(a[k]));

            if (it != rs.end()) ans = min(ans, (double)(*it - get<1>(a[k])));
            if (it != rs.begin()) ans = min(ans, (double)(get<1>(a[k]) - *prev(it)));
        }

        for (int k=i; k<j; k++) rs.insert(get<1>(a[k]));

        vector<point> pts;
        for (int k=i; k<j; k++) {
            auto [t, r, theta] = a[k];

            pts.emplace_back(r * cos(theta / 180000.0 * pi), r * sin(theta / 180000.0 * pi));
        }

        ans = min(ans, closest(pts));

        i = j;
    }

    cout << setprecision(10) << fixed;
    cout << ans << '\n';
}