#include <iostream>
using namespace std;

int main() {
	double p1, p2, p3, op, sp;
	cin >> p1 >> p2 >> p3;
	op=((1+p1/100)*(1+p2/100)*(1+p3/100)-1)*100;
	sp=op/3;
	cout << sp << endl;
	return 0;
}