func_code_string: #include <bits/stdc++.h>   using namespace std;   void check(vector<vector<long long> >& a, vector<vector<long long> >& b) {     long long n = a.size(), m = a[0].size();     for (long long i = 0; i < n; i++)       for (long long j = 0; j < m; j++)         if (a[i][j] > b[i][j]) swap(a[i][j], b[i][j]);   }   bool correct(vector<vector<long long> > a) {     long long n = a.size(), m = a[0].size();     for (long long i = 0; i < n; i++) {       for (long long j = 0; j < m; j++) {         if ((i + 1 < n && a[i][j] >= a[i + 1][j]) ||             (j + 1 < m && a[i][j] >= a[i][j + 1]) ||             (i - 1 >= 0 && a[i][j] <= a[i - 1][j]) ||             (j - 1 >= 0 && a[i][j] <= a[i][j - 1]))           return false;       }     }     return true;   }   int32_t main() {     long long n, m;     cin >> n >> m;     vector<vector<long long> > a(n, vector<long long>(m, 0)),         b(n, vector<long long>(m, 0));     for (long long i = 0; i < n; i++)       for (long long j = 0; j < m; j++) cin >> a[i][j];     for (long long i = 0; i < n; i++)       for (long long j = 0; j < m; j++) cin >> b[i][j];     check(a, b);     if (correct(a) && correct(b))       cout <<  Possible n ;     else       cout <<  Impossible n ;   }   