public class Test {

  static double integral()
  {
    final double topLimit=Math.PI/4;
    final double bottomLimit=0;
    final int steps=10000;
    final double h=(topLimit-bottomLimit)/steps;
    final double h2 = h/2;
    double sum=0;
    for (double x=bottomLimit; x<topLimit; x+=h)
    {
      double xx=x+h2; // midpoint
      double y=(xx*xx)/(Math.sin(xx)*Math.sin(xx));
      sum+=y*h;
    }
    return sum;

  }

public static void main(String[] args) {
System.out.println(integral());
}
}