public class ArmyTeleportation {
  String yes = "possible";
  String no = "impossible";
  int n, m = 3;

  boolean possibleEven(int[] x1, int[] y1, int[] x2, int[] y2, int[] xt, int[] yt) {
    int minx1 = min(x1);
    int miny1 = min(y1);
    int minx2 = min(x2);
    int miny2 = min(y2);
    for (int i = 0; i < n; i++) {
      boolean found = false;
      for (int j = 0; j < n; j++) {
        if (x1[i] - minx1 == x2[j] - minx2 && y1[i] - miny1 == y2[j] - miny2) {
          found = true;
        }
      }
      if (!found) {
        return false;
      }
    }
    long x = minx2 - minx1;
    long y = miny2 - miny1;
    if (x % 2 != 0 || y % 2 != 0) {
      return false;
    }
    x /= 2;
    y /= 2;
    long xa = xt[1] - xt[0];
    long ya = yt[1] - yt[0];
    long xb = xt[2] - xt[0];
    long yb = yt[2] - yt[0];
    if (xa * yb != xb * ya) {
      long a = (x * yb - y * xb);
      long b = (x * ya - y * xa);
      long c = (xa * yb - ya * xb);
      return (a % c == 0) && (b % c == 0);
    }
    if (x * yb != xb * y) {
      return false;
    }
    if (xa == 0) {
      long t = xa; xa = ya; ya = t;
      t = xb; xb = yb; yb = t;
      t = x; x = y; y = t;
    }
    long g = gcd(Math.abs(xa), Math.abs(xb));
    return x % g == 0;
  }

  public static long gcd(long a, long b) {
    while (a > 0) {
      long t = b % a;
      b = a;
      a = t;
    }
    return b;
  }

  int min(int[] x) {
    int res = Integer.MAX_VALUE;
    for (int i : x) {
      res = Math.min(res, i);
    }
    return res;
  }

  public String ifPossible(int[] x1, int[] y1, int[] x2, int[] y2, int[] xt, int[] yt) {
    n = x1.length;
    boolean p1 = possibleEven(x1, y1, x2, y2, xt, yt);
    for (int i = 0; i < n; i++) {
      x1[i] = 2 * xt[0] - x1[i];
      y1[i] = 2 * yt[0] - y1[i];
    }
    boolean p2 = possibleEven(x1, y1, x2, y2, xt, yt);
    return (p1 || p2) ? yes : no;
  }

}