#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
	float f, c;
	cout << fixed << showpoint << setprecision(1);

	cout << "Input the temperature in F - ";
	cin >> f;

	while (f>0)
	{


		c = 5.0/9*(f-32);

		cout << "The temperature in F - " << f << " is equal to " << c << 
			endl;
		cout << "Input the temperature in F (-1 for quit) -  ";
	        cin >> f;
	}
	return 0;
}