这个图真高级

using namespace std;
int main()
{
  double a,b,c,d[3];
  cin>>a;
  if(a<2){
  	cout<<fixed<<setprecision(2)<<a<<endl;
  }else if(2<=a and a<6){
  	cout<<fixed<<setprecision(2)<<a*a+1<<endl;
  }else if(6<=a and a<10){
  	cout<<fixed<<setprecision(2)<<sqrt(a+1)<<endl;
  }else if(10<=a){
  	cout<<fixed<<setprecision(2)<<1/(a+1)<<endl;
  }
  //╰(*°▽°*)╯(防伪标记)
  return 0;
}