#include <bits/stdc++.h>
using namespace std;
const int N = 1e7 + 10;
int n, k, m, y[310];
long double h[310][1235];
int main() {
  scanf("%d%d", &n, &k);
  m = 1234;
  long double la = 0, res;
  for (int i = 1; i <= n; i++) {
    for (int j = 0; j <= k; j++) scanf("%d", y + j);
    res = 0;
    for (int j = 0; j < k; j++) {
      long double ly = y[j], d = (long double)(y[j] - y[j + 1]) / m;
      for (int u = 1; u <= m; u++) {
        long double h0 = (ly + ly - d) / 2;
        h[j][u] = max(h[j][u], h0);
        res += h[j][u] / m;
        ly -= d;
      }
    }
    printf("%.7f\n", (double)(res - la));
    la = res;
  }
  return 0;
}
