//#include<bits/stdc++.h>
#include<algorithm>
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <cstdio>
#include <vector>
#include <string>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#include <map>
using namespace std;
#define P(a,b,c) make_pair(a,make_pair(b,c))
#define rep(i,a,n) for (int i=a;i<=n;i++)
#define per(i,a,n) for (int i=n;i>=a;i--)
#define CLR(vis) memset(vis,0,sizeof(vis))
#define MST(vis,pos) memset(vis,pos,sizeof(vis))
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef pair<int,pair<int,int> >pii;
typedef long long ll;
typedef unsigned long long ull;
const ll mod = 1000000007;
const int INF = 0x3f3f3f3f;
ll gcd(ll a, ll b) {
return b ? gcd(b, a%b) : a;
}
template<class T>inline void gmax(T &A, T B) {
(A<B)&&(A=B);//if(B>A)A=B;
}
template<class T>inline void gmin(T &A, T B) {
(A>B)&&(A=B);//if(B<A)A=B;
}
template <class T>
inline bool scan_d(T &ret) {
char c;
int sgn;
if(c=getchar(),c==EOF) return 0; //EOF
while(c!='-'&&(c<'0'||c>'9')) c=getchar();
sgn=(c=='-')?-1:1;
ret=(c=='-')?0:(c-'0');
while(c=getchar(),c>='0'&&c<='9') ret=ret*10+(c-'0');
ret*=sgn;
return 1;
}
inline void outt(int x) {
if(x>9) outt(x/10);
putchar(x%10+'0');
}
const int MAXN = 1e2+10;
int a[MAXN][MAXN];
int b[MAXN][MAXN];
int main() {
int n,m;
cin>>n>>m;
CLR(a);
CLR(b);
rep(i,1,n) {
rep(j,1,m) {
scanf("%d",&a[i][j]);
}
}
rep(i,1,n) {
rep(j,1,m) {
scanf("%d",&b[i][j]);
if(b[i][j]<a[i][j]) {
swap(a[i][j],b[i][j]);
}
}
}
rep(i,1,n) {
rep(j,1,m) {
if(a[i][j]<=a[i-1][j]||a[i][j]<=a[i][j-1]||b[i][j]<=b[i-1][j]||b[i][j]<=b[i][j-1]) {
puts("Impossible");
return 0;
}
}
}
puts("Possible");
return 0;
}