#include <bits/stdc++.h>
#define rep(i,x,y) for (int i = x; i <= y; i++)

using namespace std;

using i64 = long long;
constexpr i64 inf = 1E18;

int main() {
    int n;
    cin >> n;
    vector<int> a(n);
    rep(i,0,n-1) {
        cin >> a[i];
    }

    vector<array<array<i64, 3>, 3>> f(n);
    rep(i,0,n-1) {
        rep(j,0,2) {
            rep(k,0,2) {
                f[i][j][k] = inf;
            }
        }
    }
    f[0][0][0] = 0;
    f[0][1][1] = a[0];
    f[0][2][2] = 2 * a[0];
    rep(i,1,n-1) {
        rep(j,0,2) {
            f[i][j][0] = f[i - 1][j][2];
            f[i][j][1] = min(f[i - 1][j][1], f[i - 1][j][2]) + a[i];
            f[i][j][2] = min({f[i - 1][j][0], f[i - 1][j][1], f[i - 1][j][2]}) + 2 * a[i];
        }
    }
    rep(i,2,n-1) {
        i64 ans = inf;
        rep(j,0,2) {
            rep(k,0,2) {
                if (j + k >= 2) {
                    ans = min(ans, f[i][j][k]);
                }
            }
        }
        cout << fixed << setprecision(2) << double(ans) / 2 << " \n"[i == n - 1];
    }
    return 0;
}