#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int n, m;
  cin >> n >> m;
  bool aOk = true, bOk = true;
  vector<vector<int>> a(n, vector<int>(m)), b(n, vector<int>(m));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      cin >> a[i][j];
    }
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      cin >> b[i][j];
      int t1 = a[i][j], t2 = b[i][j];
      a[i][j] = min(t1, t2);
      b[i][j] = max(t1, t2);
      if ((i - 1) >= 0) {
        if (b[i][j] <= b[i - 1][j]) bOk = false;
        if (a[i][j] <= a[i - 1][j]) aOk = false;
      }
      if ((j - 1) >= 0) {
        if (b[i][j] <= b[i][j - 1]) bOk = false;
        if (a[i][j] <= a[i][j - 1]) aOk = false;
      }
    }
  }
  if (aOk and bOk)
    cout << "Possible\n";
  else
    cout << "Impossible\n";
}
