#include <iostream>
#include<cmath>
using namespace std;

double f (double a)
{
    return sin(a);
}

double trapezy(double a, double b, int N)
{
    double h = (b-a)/N;
    double P = (f(a)+f(b))/2;
    for(int i=1; i<N; i++)
        P += f(a+i*h);
    return P*h;
}
main()
{
    for(int i=100; i<10000000; i*=10)
    {cout.precision(15);
    cout<<trapezy(0, M_PI, 1000000)<<endl;}
}