#include using namespace std; #define INF_LL (int64)1e18 #define INF (int32)1e9 #define REP(i, n) for(int64 i = 0;i < (n);i++) #define FOR(i, a, b) for(int64 i = (a);i < (b);i++) #define all(x) x.begin(),x.end() #define fs first #define sc second using int32 = int_fast32_t; using uint32 = uint_fast32_t; using int64 = int_fast64_t; using uint64 = uint_fast64_t; using PII = pair; using PLL = pair; const double eps = 1e-10; templateinline void chmin(A &a, B b){if(a > b) a = b;} templateinline void chmax(A &a, B b){if(a < b) a = b;} int main(void){ long double r, d; cin >> r >> d; cout << fixed << setprecision(10) << sqrt(d*d-r*r) << endl; }