/******************** Author:Cdegree ********************/ #include <cstdio> #include <cstdlib> #include <cstring> #include <cmath> #include <cctype> #include <vector> #include <stack> #include <queue> #include <map> #include <algorithm> #include <iostream> #include <string> #include <set> #define X first #define Y second #define sqr(x) (x)*(x) #pragma comment(linker,"/STACK:102400000,102400000") using namespace std; const double PI = acos(-1.0); map<int, int>::iterator it; typedef long long LL ; template<typename T> void checkmin(T &x, T y) {x = min(x, y);} template<typename T> void checkmax(T &x, T y) {x = max(x, y);} const int N = 105; double a[N], dp[N]; int main() { int T, n; scanf("%d", &T); for(int t = 1; t <= T; ++t) { scanf("%d", &n); for(int i = 0; i < n; ++i) { scanf("%lf", a + i); } dp[n-1]=0; for(int i = n - 2; i >= 0; --i) { int j = min(n - 1 - i, 6); dp[i]=0; for(int k = 1; k <= j; ++k) { dp[i] += dp[i+k] + a[i+k]; } dp[i] /= j; } dp[0] += a[0]; printf("Case %d: %.6f ", t, dp[0]); } return 0; }