#include <bits/stdc++.h>
using namespace std;
const int N = 52;
int n, m, a[N][N], b[N][N], i, j;
int main() {
  cin >> n >> m;
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= m; j++) cin >> a[i][j];
  }
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= m; j++) cin >> b[i][j];
  }
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= m; j++)
      if (a[i][j] > b[i][j]) swap(a[i][j], b[i][j]);
  }
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= m; j++) {
      if (a[i][j] <= a[i][j - 1] || i < n && (a[i][j] >= a[i + 1][j])) {
        cout << "Impossible";
        return 0;
      }
    }
  }
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= m; j++) {
      if (b[i][j] <= b[i][j - 1] || i < n && (b[i][j] >= b[i + 1][j])) {
        cout << "Impossible";
        return 0;
      }
    }
  }
  cout << "Possible";
}
