online_judge_1166

#include <stdio.h>#include <stdlib.h>int main(){    double x,result;    int n,i;    while(~scanf("%lf%d",&x,&n))    {        if(n<0)            continue;        result=x;        for(i=0;i<n;i++)            result=result*2/3+x/(3*result*result);        printf("%0.6lf\n",result);    }    return 0;}