Untitled

#include <fstream>
#include <iostream>
#include <string>
using namespace std;
float v(float a, float b, float h) {
	float v;
	v = a * b * h / 3;
	return v;
}
		
int main()
{
	float a, b, h;
	ifstream in("input.txt");
	in >> a;
	in >> b;
	in >> h;
	cout << v(a, b, h);
}