#include <bits/stdc++.h>   using namespace std;   const double inf = 1e7;   const double eps = 1e-7;   int main() {     int n, width, height, begin0, begin1;     cin >> n >> width >> height >> begin0 >> begin1;     vector<pair<int, pair<double, double>>> a(n + 1);     a[0] = make_pair(0, make_pair(1, begin1 - begin0));     for (int i = 1; i <= n; ++i) {       int x, y;       cin >> a[i].first >> x >> y;       a[i].second = make_pair(1 - (double)height / y, (double)x * height / y);     }     auto check = [&](double v) {       double l = begin0, r = begin0;       for (int i = 1; i <= n; ++i) {         double delta = v * (a[i].first - a[i - 1].first);         double k0 = a[i - 1].second.first, b0 = a[i - 1].second.second;         double k1 = a[i].second.first, b1 = a[i].second.second;         double k = k0 / k1, tl, tr;         if (k1 > 0) {           tl = (b0 - delta - b1) / k1;           tr = (b0 + delta - b1) / k1;         } else {           tl = (b0 + delta - b1) / k1;           tr = (b0 - delta - b1) / k1;         }         if (fabs(k0 - k1) < eps) {           tl = max(tl, -delta);           tr = min(tr, delta);           if (tl > tr + eps) {             return false;           }           l += tl;           r += tr;         } else {           double ml = (tl + delta) / (1 - k), mr = (tr - delta) / (1 - k);           double nl = inf, nr = -inf;           if (k > 1) {             {               double left = max(l, mr), right = min(r, ml);               if (right >= left - eps) {                 nl = min(nl, left - delta);                 nr = max(nr, right + delta);               }             }             {               double left = max(l, max(ml, mr)), right = r;               if (right >= left - eps) {                 right = min(right, (delta - tl) / (k - 1));                 if (right >= left - eps) {                   nl = min(nl, k * left + tl);                   nr = max(nr, right + delta);                 }               }             }             {               double left = l, right = min(r, min(ml, mr));               if (right >= left - eps) {                 left = max(left, -(delta + tr) / (k - 1));                 if (right >= left - eps) {                   nl = min(nl, left - delta);                   nr = max(nr, k * right + tr);                 }               }             }             {               double left = max(l, ml), right = min(r, mr);               if (right >= left - eps) {                 nl = min(nl, k * left + tl);                 nr = max(nr, k * right + tr);               }             }           } else {             {               double left = max(l, ml), right = min(r, mr);               if (right >= left - eps) {                 if (k > 0) {                   nl = min(nl, k * left + tl);                   nr = max(nr, k * right + tr);                 } else {                   nl = min(nl, k * right + tl);                   nr = max(nr, k * left + tr);                 }               }             }             {               double left = l, right = min(r, min(ml, mr));               if (right >= left - eps) {                 left = max(left, (tl - delta) / (1 - k));                 if (right >= left - eps) {                   if (k > 0) {                     nl = min(nl, k * left + tl);                   } else {                     nl = min(nl, k * right + tl);                   }                   nr = max(nr, right + delta);                 }               }             }             {               double left = max(l, max(ml, mr)), right = r;               if (right >= left - eps) {                 right = min(right, (tr + delta) / (1 - k));                 if (right >= left - eps) {                   nl = min(nl, left - delta);                   if (k > 0) {                     nr = max(nr, k * right + tr);                   } else {                     nr = max(nr, k * left + tr);                   }                 }               }             }             {               double left = max(l, mr), right = min(r, ml);               if (right >= left - eps) {                 nl = min(nl, left - delta);                 nr = max(nr, right + delta);               }             }           }           if (nl > nr + eps) {             return false;           }           l = nl;           r = nr;         }         l = max(l, (double)0);         r = min(r, (double)width);         if (k1 > 0) {           l = max(l, -b1 / k1);           r = min(r, (width - b1) / k1);         } else {           l = max(l, (width - b1) / k1);           r = min(r, -b1 / k1);         }         if (l > r + eps) {           return false;         }       }       return true;     };     if (!check(width + 1)) {       cout << -1 << endl;     } else {       double l = 0, r = width;       for (int t = 0; t < 50; ++t) {         double m = (l + r) / 2;         if (check(m)) {           r = m;         } else {           l = m;         }       }       cout << fixed << setprecision(6) << r << endl;     }     return 0;   }