int main(){
double a=1,b=2;
while (fabs(b-a)>0.01){
double c = (a+b)/2.0;
if ((2-a*a*a)*(2-c*c*c) < 0)
b=c;
else
a=c;
}
printf("%8.3lg\n",(a+b)/2.0);
return 0;
}