#include <iostream>
#include <bits/stdc++.h>
using namespace std;
float a,b;
float f(float x)
{
    return x*x-sin(x);
}
int main()
{
    int j=0;
    float integrala=0;
    cin>>a>>b;
    for(j=1; j<=10000; j++)
        integrala=integrala+f((float)(((b-a)*j)/20000)*(float)((b-a)/10000));
    cout<<integrala;
}