#include <bits/stdc++.h> using namespace std; using LL = long long int; #define incII(i, l, r) for(LL i = (l) ; i <= (r); i++) #define incIX(i, l, r) for(LL i = (l) ; i < (r); i++) #define incXI(i, l, r) for(LL i = (l) + 1; i <= (r); i++) #define incXX(i, l, r) for(LL i = (l) + 1; i < (r); i++) #define decII(i, l, r) for(LL i = (r) ; i >= (l); i--) #define decIX(i, l, r) for(LL i = (r) - 1; i >= (l); i--) #define decXI(i, l, r) for(LL i = (r) ; i > (l); i--) #define decXX(i, l, r) for(LL i = (r) - 1; i > (l); i--) #define inc(i, n) incIX(i, 0, n) #define dec(i, n) decIX(i, 0, n) #define inc1(i, n) incII(i, 1, n) #define dec1(i, n) decII(i, 1, n) auto inII = [](auto x, auto l, auto r) { return (l <= x && x <= r); }; auto inIX = [](auto x, auto l, auto r) { return (l <= x && x < r); }; auto inXI = [](auto x, auto l, auto r) { return (l < x && x <= r); }; auto inXX = [](auto x, auto l, auto r) { return (l < x && x < r); }; auto setmin = [](auto & a, auto b) { return (b < a ? a = b, true : false); }; auto setmax = [](auto & a, auto b) { return (b > a ? a = b, true : false); }; auto setmineq = [](auto & a, auto b) { return (b <= a ? a = b, true : false); }; auto setmaxeq = [](auto & a, auto b) { return (b >= a ? a = b, true : false); }; #define PB push_back #define EB emplace_back #define MP make_pair #define MT make_tuple #define FI first #define SE second #define FR front() #define BA back() #define ALL(c) c.begin(), c.end() #define RALL(c) c.rbegin(), c.rend() #define RV(c) reverse(ALL(c)) #define SC static_cast #define SI(c) SC<int>(c.size()) #define SL(c) SC<LL >(c.size()) #define RF(e, c) for(auto & e: c) #define SF(c, ...) for(auto & [__VA_ARGS__]: c) #define until(e) while(! (e)) #define if_not(e) if(! (e)) #define ef else if #define UR assert(false) auto * IS = & cin; auto * OS = & cout; array<string, 3> SEQ = { "", " ", "" }; // input template<typename T> T in() { T a; (* IS) >> a; return a; } // input: tuple template<int I, typename U> void tin_(istream & is, U & t) { if constexpr(I < tuple_size<U>::value) { is >> get<I>(t); tin_<I + 1>(is, t); } } template<typename ... T> istream & operator>>(istream & is, tuple<T ...> & t) { tin_<0>(is, t); return is; } template<typename ... T> auto tin() { return in<tuple<T ...>>(); } // input: array template<typename T, size_t N> istream & operator>>(istream & is, array<T, N> & a) { RF(e, a) { is >> e; } return is; } template<typename T, size_t N> auto ain() { return in<array<T, N>>(); } // input: multi-dimensional vector template<typename T> T vin() { T v; (* IS) >> v; return v; } template<typename T, typename N, typename ... M> auto vin(N n, M ... m) { vector<decltype(vin<T, M ...>(m ...))> v(n); inc(i, n) { v[i] = vin<T, M ...>(m ...); } return v; } // input: multi-column (tuple<vector>) template<typename U, int I> void colin_([[maybe_unused]] U & t) { } template<typename U, int I, typename A, typename ... B> void colin_(U & t) { get<I>(t).PB(in<A>()); colin_<U, I + 1, B ...>(t); } template<typename ... T> auto colin(int n) { tuple<vector<T> ...> t; inc(i, n) { colin_<tuple<vector<T> ...>, 0, T ...>(t); } return t; } // output void out_([[maybe_unused]] string s) { } template<typename A> void out_([[maybe_unused]] string s, A && a) { (* OS) << a; } template<typename A, typename ... B> void out_(string s, A && a, B && ... b) { (* OS) << a << s; out_(s, b ...); } auto outF = [](auto x, auto y, auto z, auto ... a) { (* OS) << x; out_(y, a ...); (* OS) << z << flush; }; auto out = [](auto ... a) { outF("", " " , "\n", a ...); }; auto outS = [](auto ... a) { outF("", " " , " " , a ...); }; auto outL = [](auto ... a) { outF("", "\n", "\n", a ...); }; auto outN = [](auto ... a) { outF("", "" , "" , a ...); }; // output: multi-dimensional vector template<typename T> ostream & operator<<(ostream & os, vector<T> const & v) { os << SEQ[0]; inc(i, SI(v)) { os << (i == 0 ? "" : SEQ[1]) << v[i]; } return (os << SEQ[2]); } template<typename T> void vout_(T && v) { (* OS) << v; } template<typename T, typename A, typename ... B> void vout_(T && v, A a, B ... b) { inc(i, SI(v)) { (* OS) << (i == 0 ? "" : a); vout_(v[i], b ...); } } template<typename T, typename A, typename ... B> void vout (T && v, A a, B ... b) { vout_(v, a, b ...); (* OS) << a << flush; } template<typename T, typename A, typename ... B> void voutN(T && v, A a, B ... b) { vout_(v, a, b ...); (* OS) << flush; } // ---- ---- const double TAU = atan2(0, -1) * 2.0; int main() { auto [h, r] = ain<double, 2>(); double s = -8.245 + 6.807 * h + 7.073 * r * TAU; printf("%.12f\n", s); }