#define _CRT_SECURE_NO_WARNINGS #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include //#include "util.h" using namespace std; typedef unsigned uint; typedef long long lint; typedef unsigned long long ulint; //呪文 template ostream& operator << (ostream& ostr, const pair<_KTy, _Ty>& m) { cout << "{" << m.first << ", " << m.second << "}"; return ostr; } template ostream& operator << (ostream& ostr, const map<_KTy, _Ty>& m) { if (m.empty()) { cout << "{ }"; return ostr; } cout << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; } template ostream& operator << (ostream& ostr, const vector<_Ty>& v) { if (v.empty()) { cout << "{ }"; return ostr; } cout << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; } template ostream& operator << (ostream& ostr, const set<_Ty>& s) { if (s.empty()) { cout << "{ }"; return ostr; } cout << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; } template void print(T* v, int N) { if (N == 0) cout << "{ }"; cout << "{" << v[0]; for (int i = 1; i < N; i++) cout << ", " << v[i]; cout << "}"; } #define PI 3.14159265358979323846 #define EPS 1e-8 #define all(x) (x).begin(), (x).end() int yuki0538() { lint b1, b2, b3; cin >> b1 >> b2 >> b3; cout << (b2 * b2 + b3 * b3 - b1 * b3 - b2 * b3) / (b2 - b1) << endl; return 0; } int main() { //clock_t start, end; //start = clock(); yuki0538(); //end = clock(); //printf("%d msec.\n", end - start); return 0; }