#include <bits/stdc++.h>
inline long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
inline void sub(long long &a, long long b) {
  a -= b;
  if (a < 0) a += 1000000007;
}
inline void add(long long &a, long long b) {
  a += b;
  if (a >= 1000000007) a -= 1000000007;
}
template <typename T>
inline T const &MAX(T const &a, T const &b) {
  return a > b ? a : b;
}
template <typename T>
inline T const &MIN(T const &a, T const &b) {
  return a < b ? a : b;
}
inline long long qp(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % 1000000007;
    a = a * a % 1000000007, b >>= 1;
  }
  return ans;
}
inline long long qp(long long a, long long b, long long c) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % c;
    a = a * a % c, b >>= 1;
  }
  return ans;
}
using namespace std;
const unsigned long long ba = 233;
const double eps = 1e-6;
const long long INF = 0x3f3f3f3f3f3f3f3f;
const int N = 1000 + 10, maxn = 10000000 + 10, inf = 0x3f3f3f3f;
int a[N][N], b[N][N];
int main() {
  int n, m;
  scanf("%d%d", &n, &m);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++) scanf("%d", &a[i][j]);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++) scanf("%d", &b[i][j]);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++) {
      if (i - 1 >= 1) {
        if (a[i - 1][j] < a[i][j] && b[i - 1][j] < b[i][j])
          ;
        else if (a[i - 1][j] < b[i][j] && b[i - 1][j] < a[i][j])
          ;
        else
          return 0 * puts("Impossible");
      }
      if (j - 1 >= 1) {
        if (a[i][j - 1] < a[i][j] && b[i][j - 1] < b[i][j])
          ;
        else if (a[i][j - 1] < b[i][j] && b[i][j - 1] < a[i][j])
          ;
        else
          return 0 * puts("Impossible");
      }
    }
  puts("Possible");
  return 0;
}
