#include <bits/stdc++.h>
using namespace std;
void swap(int ar[], int i, int j) {
  int aux = ar[j];
  ar[j] = ar[i];
  ar[i] = ar[j];
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, m;
  cin >> n >> m;
  int Ma[n][m];
  int Mb[n][m];
  for (int i = 0; i < n; i++)
    for (int k = 0; k < m; k++) cin >> Ma[i][k];
  for (int i = 0; i < n; i++)
    for (int k = 0; k < m; k++) {
      int aux;
      cin >> aux;
      if (aux <= Ma[i][k]) {
        int aux2 = Ma[i][k];
        Ma[i][k] = aux;
        Mb[i][k] = aux2;
      } else
        Mb[i][k] = aux;
    }
  for (int i = 0; i < n; i++)
    for (int k = 1; k < m; k++)
      if (Ma[i][k] <= Ma[i][k - 1] || Mb[i][k] <= Mb[i][k - 1]) {
        cout << "Impossible";
        return 0;
      }
  for (int k = 0; k < m; k++)
    for (int i = 1; i < n; i++)
      if (Ma[i][k] <= Ma[i - 1][k] || Mb[i][k] <= Mb[i - 1][k]) {
        cout << "Impossible";
        return 0;
      }
  cout << "Possible";
  return 0;
}
