#include <iostream>

using namespace std;

int main() {
  
      int trials{100'000};
      int hits = 0;

      double x , y;


      for(int i = 0; i < trials; ++i) {
          x = rand() / static_cast<double>(RAND_MAX);
          y = rand() / static_cast<double>(RAND_MAX);
          if (x*x + y*y <= 1)  {
             ++hits;
          }
      }

      cout << 4 * hits / static_cast<double> (trials) << endl;

      return 0;
}