#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
    int n;
    cin >> n;
    queue<ll> q;
    int x;
    int sum = 0.0;
    int i = 0;
    while(1){
        i++;
        cin >> x;
        if(x == - 1)
            break;
        sum = sum + x;
        if(i > n){
            sum = sum - q.front();
            q.pop();
        }
        q.push(x);
        ll d = min(i, n);
        cout << (double)(sum)/q.size() << " ";
    }
    cout << "\n";
    return 0;
}
 

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NQo1MSA2MiAyNCA1MSA3OSAzMyA3MiA3OCA4NCA0MiAtMQ==

5
51 62 24 51 79 33 72 78 84 42 -1