#include <bits/stdc++.h>   using namespace std;   const int MAX = 510;   int n, m;   double xa, ya, x2, y2;   double v, vx1, vx2, vy1, vy2, t;   int check(double k) {     double x, y;     x = xa + vx1 * min(k, t) + vx2 * max(0.0, k - t);     y = ya + vy1 * min(k, t) + vy2 * max(0.0, k - t);     double dist = sqrt((x - x2) * (x - x2) + (y - y2) * (y - y2));     if (v * k >= dist) return 1;     return 0;   }   int main() {     int i, j, k;     while (~scanf( %lf%lf%lf%lf , &xa, &ya, &x2, &y2)) {       scanf( %lf%lf , &v, &t);       scanf( %lf%lf , &vx1, &vy1);       scanf( %lf%lf , &vx2, &vy2);       double l = 0.0, r = 1e9;       while ((r - l) > 1e-6) {         double mid = (l + r) / 2;         if (check(mid))           r = mid;         else           l = mid;       }       printf( %.10lf n , l);     }     return 0;   }   