#include <iostream>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>
#include <math.h>

using namespace std;

typedef long long ll;


int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int x1, y1, x2, y2;
    int n;
    cin >> x1 >> y1 >> x2 >> y2 >> n;

    vector <pair<int, int>> cs(n);
    vector <int> t(n);
    for (int i = 0; i < n; i++) {
        int a, b;
        cin >> a >> b;
        cs[i] = { a, b };
        cin >> t[i];
    }

    double ans = 1e9;

    for (int i = 0; i < n; i++) {
        double c = 0;
        c += sqrt((cs[i].first - x1) * (cs[i].first - x1) + (cs[i].second - y1) * (cs[i].second - y1));
        c += t[i];
        c += sqrt((x2 - cs[i].first) * (x2 - cs[i].first) + (y2 - cs[i].second) * (y2 - cs[i].second));
        ans = min(ans, c);
    }

    cout << fixed;
    cout.precision(10);
    cout << ans;

}