#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
	cout.setf(ios::scientific);
	cout.precision(4);
	double val = 436.234509876;

	cout<<val<<endl;

	cout.setf(ios::showpoint);
	val=12.0;
	cout<<val<<endl;
	
	cout.setf(ios::fixed);
	cout.precision(8);
	val=1.694873572548555e-19;
	cout<<val<<endl;
	
	return 0;
}