Lul

#include <iostream>
#include <math.h>
#include <cmath>

using namespace std;

double sum(int k, double x);

int main()
{
    int k = 1;
    for(double i = -0.5 ; i <-0.1 ; i+=0.1){
        k = 1;
        while(abs(sum(k, i)-sum(k+1, i))<0.001)
            k++;
        cout<<i<<" "<<k<<" "<<sum(k, i)<<endl;
    }
    for(double i = 0.1 ; i <=0.5 ; i+=0.1){
        k = 1;
        while(abs(sum(k, i)-sum(k+1, i))<0.001)
            k++;
        cout<<i<<" "<<k<<" "<<sum(k, i)<<endl;
    }

    return 0;
}


double sum(int k, double x){
    double totalSum = 0;
    double a, b;
    for(double i = 1 ; i<=k ; i++){
        a = pow(-1, i+1)/i;
        b = (pow(-1, i)*6)/(pow(i,3)*pow(M_PI,2));
        totalSum += (a+b)*sin(i*M_PI*x);
    }
    return totalSum;
}