#include <bits/stdc++.h>   using namespace std;   const double error = 1e-7;   double v, r;   bool puede(double t, double dist) {     dist -= v * t;     if (dist <= 0) return true;     double tvuelta = r * 2 * M_PI / v;     t -= int(t / tvuelta) * tvuelta;     double a = t * v / r;     return dist <= 2 * r * sin(a / 2.0);   }   int main() {     cout.setf(ios::fixed);     cout.precision(10);     int n;     cin >> n >> r >> v;     for (int cas = 0; cas < n; cas++) {       int s, f;       cin >> s >> f;       double inf = 0;       double sup = 2000000000;       double d = f - s;       while (inf + error < sup) {         double med = (inf + sup) / 2.0;         if (puede(med, d))           sup = med;         else           inf = med;       }       cout << inf << endl;     }   }   