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

double data[20]={2,6,8};
int K=3,P;
double clac(double x){
	double sum=-1;
	for(int i=0;i<K;++i){
		sum*=x-data[i];
	}
	return sum;
}
int main(){
	printf("%.30lf\n",clac(7.097167));
	printf("%.30lf\n",clac(7.097168));
}