#include <iostream>

int z; // global variable
void deg_f_to_c(double deg_f, double &deg_c);

int main()
{
	double deg_f, deg_c;
	cout << "Enter deg f: ";
	cin >> deg_f;
	deg_f_to_c(deg_f, deg_c);
	cout << "In celcius, that is " << deg_c << " degrees\n";
}

void deg_f_to_c(double deg_f, double &deg_c)
{
	deg_c = (deg_f-32)*5./9.;
}