#line 2 "cp-library/src/cp-template.hpp" #include using namespace std; using ll = long long; using ld = long double; using uint = unsigned int; using ull = unsigned long long; using i32 = int; using u32 = unsigned int; using i64 = long long; using u64 = unsigned long long; using i128 = __int128_t; template < class T > bool chmin(T& a, T b) { if(a > b) { a = b; return true; } return false; } template < class T > bool chmax(T& a, T b) { if(a < b) { a = b; return true; } return false; } #line 2 "cp-library/src/utility/rep_itr.hpp" template < class T > struct itr { T i, d; constexpr itr(const T i) noexcept : i(i), d(1) {} constexpr itr(const T i, const T d) noexcept : i(i), d(d) {} void operator++() noexcept { i += d; } constexpr int operator*() const noexcept { return i; } constexpr bool operator!=(const itr x) const noexcept { return d > 0 ? i < x.i : i > x.i; } }; template < class T > struct rep { const itr< T > s, t; constexpr rep(const T t) noexcept : s(0), t(t) {} constexpr rep(const T s, const T t) noexcept : s(s), t(t) {} constexpr rep(const T s, const T t, const T d) noexcept : s(s, d), t(t, d) {} constexpr auto begin() const noexcept { return s; } constexpr auto end() const noexcept { return t; } }; template < class T > struct revrep { const itr < T > s, t; constexpr revrep(const T t) noexcept : s(t - 1, -1), t(-1, -1) {} constexpr revrep(const T s, const T t) noexcept : s(t - 1, -1), t(s - 1, -1) {} constexpr revrep(const T s, const T t, const T d) noexcept : s(t - 1, -d), t(s - 1, -d) {} constexpr auto begin() const noexcept { return s; } constexpr auto end() const noexcept { return t; } }; #line 2 "cp-library/src/utility/io.hpp" namespace scanner { struct sca { template < class T > operator T() { T s; cin >> s; return s; } }; struct vec { int n; vec(int n) : n(n) {} template < class T > operator vector< T >() { vector< T > v(n); for(T& x : v) cin >> x; return v; } }; struct mat { int h,w; mat(int h, int w) : h(h), w(w) {} template < class T > operator vector< vector< T > >() { vector m(h, vector< T >(w)); for(vector< T >& v : m) for(T& x : v) cin >> x; return m; } }; struct speedup { speedup() { cin.tie(0); ios::sync_with_stdio(0); } } speedup_instance; } scanner::sca in() { return scanner::sca(); } scanner::vec in(int n) { return scanner::vec(n); } scanner::mat in(int h, int w) { return scanner::mat(h, w); } namespace printer { void precision(int d) { cout << fixed << setprecision(d); } void flush() { cout.flush(); } } template < class T > ostream& operator<<(ostream& os, const std::vector< T > a) { int n = a.size(); for(int i : rep(n)) { os << a[i]; if(i != n - 1) os << ' '; } return os; } int print() { cout << '\n'; return 0; } template < class head, class... tail > int print(head&& h, tail&&... t) { cout << h; if(sizeof...(tail)) cout << ' '; return print(forward(t)...); } template < class T > int print_n(const std::vector< T > a) { int n = a.size(); for(int i : rep(n)) cout << a[i] << "\n"; return 0; } #line 2 "cp-library/src/utility/key_val.hpp" template < class K, class V > struct key_val { K key; V val; key_val() {} key_val(K key, V val) : key(key), val(val) {} }; #line 2 "cp-library/src/utility/vec_op.hpp" template < class T > key_val< int, T > max_of(const vector< T >& a) { int i = max_element(a.begin(), a.end()) - a.begin(); return {i, a[i]}; } template < class T > key_val< int, T > min_of(const vector< T >& a) { int i = min_element(a.begin(), a.end()) - a.begin(); return {i, a[i]}; } template < class T > T sum_of(const vector< T >& a) { T sum = 0; for(const T x : a) sum += x; return sum; } template < class T > vector freq_of(const vector< T >& a, T L, T R) { vector res(R - L); for(const T x : a) res[x - L]++; return res; } template < class T > vector freq_of(const vector< T >& a, T R) { return freq_of(a, T(0), R); } template < class T > struct prefix_sum { vector< T > s; prefix_sum(const vector< T >& a) : s(a) { s.insert(s.begin(), T(0)); for(int i : rep(a.size())) s[i + 1] += s[i]; } // [L, R) T sum(int L, int R) { return s[R] - s[L]; } }; #line 3 "cp-library/src/utility/heap.hpp" template < class T > using heap_min = std::priority_queue< T, std::vector< T >, std::greater< T > >; template < class T > using heap_max = std::priority_queue< T, std::vector< T >, std::less< T > >; #line 21 "cp-library/src/cp-template.hpp" #line 1 "cp-library/src/algorithm/bin_search.hpp" template < class T, class F > T bin_search(T ok, T ng, F& f) { while(abs(ok - ng) > 1) { T mid = (ok + ng) / 2; (f(mid) ? ok : ng) = mid; } return ok; } template < class T, class F > T bin_search_real(T ok, T ng, F& f, int step = 80) { while(step--) { T mid = (ok + ng) / 2; (f(mid) ? ok : ng) = mid; } return ok; } #line 2 "cp-library/src/algorithm/argsort.hpp" template < class T > std::vector< int > argsort(const std::vector< T > &a) { std::vector< int > ids((int)a.size()); std::iota(ids.begin(), ids.end(), 0); std::sort(ids.begin(), ids.end(), [&](int i, int j) { return a[i] < a[j] || (a[i] == a[j] && i < j); }); return ids; } #line 2 "A.cpp" int main() { int N = in(); ld R = in(); R = 1 - R; ld ans = 100.0 * (1 - pow(R, N)) / (1 - R); printer::precision(20); print(ans); }