#include <iostream>
#include <math.h>

using namespace std;

class Urav {
    private:
        int kefa;
        int kefb;
        int kefc;
    public:
        Urav (int a, int b, int c):kefa(a), kefb(b), kefc(c)
        {}
        int sum() {
            return kefb*kefb-4*kefa*kefc;
        }


};

int main(){
int a,b,c;
cin >> a; cin >> b; cin >> c;
cout << "D = ";
Urav n1(a,b,c);
cout << n1.sum()<<endl;
}