import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.util.Scanner;
public class AverageofSlidingWindows {
public static class Queue {
int front, ms, cs, rear;
int[] arr;
public Queue(int n) {
arr = new int[n];
cs = 0;
ms = n;
front = 0;
rear = n - 1;
}
void push(int data) {
if (cs == ms)
return;
rear = (rear + 1) % ms;
arr[rear] = data;
cs++;
}
void pop() {
if (cs == 0)
return;
front = (front + 1) % ms;
cs--;
}
boolean empty() {
return cs == 0;
}
boolean full() {
return cs == ms;
}
int front() {
return arr[front];
}
int size() {
return cs;
}
}
public static void circularQueue(int k) {
Scanner scn = new Scanner(System.in);
DecimalFormat df = new DecimalFormat("#.0000");
df.setRoundingMode(RoundingMode.CEILING);
Queue q = new Queue(k);
int sum = 0;
int n = scn.nextInt();
while (n != -1) {
sum = sum + n;
if (q.full()) {
sum = sum - q.front();
q.pop();
}
q.push(n);
System.out.print(df.format((double) sum / q.size()) + " ");
n = scn.nextInt();
}
}
public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
// size of the window
int k = scn.nextInt();
circularQueue(k);
}
}