#include #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,fma,abm,mmx,avx,avx2") #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--) #define all(x) (x).begin(), (x).end() #define sz(x) int(x.size()) #define yn(joken) cout<<((joken) ? "Yes" : "No")<<"\n" #define YN(joken) cout<<((joken) ? "YES" : "NO")<<"\n" using namespace std; using ll = long long; using vi = vector; using vl = vector; using vs = vector; using vc = vector; using vd = vector; using vld = vector; using vvi = vector>; using vvl = vector>; using vvs = vector>; using vvc = vector>; using vvd = vector>; using vvld = vector>; using vvvi = vector>>; using vvvl = vector>>; using vvvvi = vector>>>; using vvvvl = vector>>>; using pii = pair; using pll = pair; const int INF = 1e9; const ll LINF = 2e18; template bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; } bool ispow2(int i) { return i && (i & -i) == i; } bool ispow2(ll i) { return i && (i & -i) == i; } template vector make_vec(size_t a) { return vector(a); } template auto make_vec(size_t a, Ts... ts) { return vector(ts...))>(a, make_vec(ts...)); } template istream& operator>>(istream& is, vector& v) { for (int i = 0; i < int(v.size()); i++) { is >> v[i]; } return is; } template ostream& operator<<(ostream& os, const vector& v) { for (int i = 0; i < int(v.size()); i++) { os << v[i]; if (i < int(v.size()) - 1) os << ' '; } return os; } static uint32_t RandXor(){ static uint32_t x=123456789; static uint32_t y=362436069; static uint32_t z=521288629; static uint32_t w=88675123; uint32_t t; t=x^(x<<11); x=y; y=z; z=w; return w=(w^(w>>19))^(t^(t>>8)); } static double Rand01(){ return (RandXor()+0.5)*(1.0/UINT_MAX); } void solve(){ int N,K; cin>>N>>K; vld DP1(6*N+1),DP2(6*N+1); DP1[0]=1; DP2[0]=1; long double p=1; p/=6; rep(i,N){ vld NDP1(6*N+1); rep(j,6*N+1){ for(int k=1;k<=6;k++){ if(j+k<=6*N) NDP1[j+k]+=DP1[j]*p; } } swap(DP1,NDP1); } rep(i,N-K){ vld NDP2(6*N+1); rep(j,6*N+1){ for(int k=1;k<=6;k++){ if(j+k<=6*N) NDP2[j+k]+=DP2[j]*p; } } swap(DP2,NDP2); } rep(i,K){ vld NDP2(6*N+1); rep(j,6*N+1){ for(int k=4;k<=6;k++){ if(j+k<=6*N) NDP2[j+k]+=DP2[j]*2*p; } } swap(DP2,NDP2); } long double ans=0; rep(i,6*N+1){ for(int j=i+1;j<=6*N;j++){ ans+=DP1[i]*DP2[j]; } } cout<