#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long read() {
  long long s = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    s = s * 10 + ch - '0';
    ch = getchar();
  }
  return s * f;
}
inline void print(long long *f, long long len) {
  for (long long i = 0; i < len; i++) printf("%lld ", f[i]);
  puts("");
}
long double v[1010100];
signed main() {
  n = read(), k = read();
  long long blo = 1.0 * 1000000 / k;
  for (long long nums = 1, numsend = n; nums <= numsend; ++nums) {
    long long x, y;
    long double nw;
    x = read();
    long double sum = 0;
    for (long long i = 0, iend = k - 1; i <= iend; ++i) {
      y = read();
      long double l = (long double)(y - x) / blo;
      for (long long j = 0, jend = blo; j <= jend; ++j) {
        nw = x + l * j;
        if (nw > v[i * blo + j]) {
          sum += nw - v[i * blo + j];
          v[i * blo + j] = nw;
        }
      }
      x = y;
    }
    printf("%.4Lf\n", sum / blo);
  }
}
