#include #include #include using namespace std; #define int long long #define REP(i,m,n) for(int i=(m);i<(n);i++) #define rep(i,n) REP(i,0,n) #define pb push_back #define all(a) a.begin(),a.end() #define rall(c) (c).rbegin(),(c).rend() #define mp make_pair #define endl '\n' //#define vec vector //#define mat vector > #define fi first #define se second #define double long double typedef long long ll; typedef unsigned long long ull; typedef pair pll; //typedef long double ld; typedef complex Complex; const ll INF=1e9+7; const ll MOD=998244353; const ll inf=INF*INF; const ll mod=INF; const ll MAX=2000010; const double PI=acos(-1.0); typedef vector > mat; typedef vector vec; void solve(){ ll a,b,c,n;cin>>a>>b>>c>>n; vector > > >dp(n+1,vector > >(a+1,vector >(b+1,vector(c+1)))); dp[0][a][b][c]=1.0; rep(i,n){ rep(j,a+1){ rep(k,b+1){ rep(l,c+1){ if(j+k+l<2)continue; double al=1.0; if(j>=2){ dp[i+1][j-1][k][l]+=dp[i][j][k][l]*(double)j*(double)(j-1)/(double)(j+k+l)/(double)(j+k+l-1); al-=(double)j*(double)(j-1)/(double)(j+k+l)/(double)(j+k+l-1); } if(k>=2){ dp[i+1][j][k-1][l]+=dp[i][j][k][l]*(double)k*(double)(k-1)/(double)(j+k+l)/(double)(j+k+l-1); al-=(double)k*(double)(k-1)/(double)(j+k+l)/(double)(j+k+l-1); } if(l>=2){ dp[i+1][j][k][l-1]+=dp[i][j][k][l]*(double)l*(double)(l-1)/(double)(j+k+l)/(double)(j+k+l-1); al-=(double)l*(double)(l-1)/(double)(j+k+l)/(double)(j+k+l-1); } dp[i+1][j][k][l]+=dp[i][j][k][l]*al; } } } } double x=0,y=0,z=0; rep(j,a+1){ rep(k,b+1){ rep(l,c+1){ x+=dp[n][j][k][l]*(double)(a-j); y+=dp[n][j][k][l]*(double)(b-k); z+=dp[n][j][k][l]*(double)(c-l); } } } cout<