//example of how to use setprecision

#include<iostream>
#include<iomanip>

using namespace std;

int main()
{
	double x = 122.45678;

	cout<<x<<endl;

	cout<<fixed<<setprecision(1)<<x<<endl;

	cout<<fixed<<setprecision(2)<<x<<endl;

	cout<<fixed<<setprecision(3)<<x<<endl;

	return 0;	
}