#include <bits/stdc++.h>
using namespace std;
const int N = 1e6;
int n, k;
long double a[N + 7];
int main() {
  scanf("%d%d", &n, &k);
  int m = N / k;
  for (int i = 1; i <= n; i++) {
    int x1;
    long double ans = 0;
    scanf("%d", &x1);
    for (int j = 0; j < k; j++) {
      int x2;
      scanf("%d", &x2);
      long double kk = (long double)(x2 - x1) / m;
      for (int t = 0; t <= m; t++) {
        long double tmp = (long double)x1 + kk * t;
        if (tmp > a[j * m + t]) {
          ans += tmp - a[j * m + t];
          a[j * m + t] = tmp;
        }
      }
      x1 = x2;
    }
    ans /= m;
    cout << ans << endl;
  }
  return 0;
}
