#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define rep(i,a,b) for(int i=(a);i<(b);++i) #define MOD 1000000007 #define int long long using ll = long long; using namespace std; const int INF = 1LL << 50; using P = pair; template bool chmin(T &a, T b) { if (a > b) { a = b; return true; } else { return false; } } template bool chmax(T &a, T b) { if (a < b) { a = b; return true; } else { return false; } } struct Setup { Setup() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); } } SETUP; signed main() { double r, d; cin >> r >> d; r *= r, d *= d; double ans = d - r; ans = sqrt(ans); cout << ans << endl; }