Language: C++

using System;

class A {
    string[] Rs(){
		return Console.ReadLine().Split(' ');
	}
    public void run(){
        string[] HW = Rs();
        int H = int.Parse(HW[0]), W = int.Parse(HW[1]);
        int[,] A = new int[H,W];
        for(int i=0;i<H;i++){
            string inp = Console.ReadLine();
            for(int j=0;j<W;j++){
                A[i,j] = (inp[j]=='#')?1:0;
            }
        }
        Func<int, int, bool> f = null;
        f = (x, y) =>{
            if(x==H-1 && y==W-1) return true;
            bool ans = false;
            if( x<H-1 && A[x+1,y]==1 && (y==W-1 || (A[x,y+1]==0))){
                ans = ans || f(x+1, y);
            }
            if( y<W-1&& A[x,y+1]==1 && (x==H-1 || (A[x+1,y] == 0))){
                ans = ans || f(x, y+1);
            }
            return ans;
        };
        
        if(f(0,0)){
            Console.WriteLine("Possible");
        } else {
            Console.WriteLine("Impossible");
        }
        
    }
    
}

class Program {
    static void Main(string[] args){
        A a = new A();
        a.run();
    }
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:4:5: error: 'string' does not name a type
    4 |     string[] Rs(){
      |     ^~~~~~
a.cc:7:11: error: expected ':' before 'void'
    7 |     public void run(){
      |           ^~~~~
      |           :
a.cc:38:2: error: expected ';' after class definition
   38 | }
      |  ^
      |  ;
a.cc: In member function 'void A::run()':
a.cc:8:9: error: 'string' was not declared in this scope
    8 |         string[] HW = Rs();
      |         ^~~~~~
a.cc:8:16: error: expected primary-expression before ']' token
    8 |         string[] HW = Rs();
      |                ^
a.cc:9:17: error: expected primary-expression before 'int'
    9 |         int H = int.Parse(HW[0]), W = int.Parse(HW[1]);
      |                 ^~~
a.cc:10:13: error: expected identifier before ',' token
   10 |         int[,] A = new int[H,W];
      |             ^
a.cc:10:13: error: expected ']' before ',' token
a.cc:10:12: error: structured binding declaration cannot have type 'int'
   10 |         int[,] A = new int[H,W];
      |            ^
a.cc:10:12: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:10:12: error: empty structured binding declaration
a.cc:10:16: error: expected initializer before 'A'
   10 |         int[,] A = new int[H,W];
      |                ^
a.cc:12:20: error: expected ';' before 'inp'
   12 |             string inp = Console.ReadLine();
      |                    ^~~
a.cc:13:27: error: 'W' was not declared in this scope
   13 |             for(int j=0;j<W;j++){
      |                           ^
a.cc:14:18: error: structured binding declaration cannot have type 'A'
   14 |                 A[i,j] = (inp[j]=='#')?1:0;
      |                  ^~~~~
a.cc:14:18: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:14:21: error: redeclaration of 'auto j'
   14 |                 A[i,j] = (inp[j]=='#')?1:0;
      |                     ^
a.cc:13:21: note: 'int j' previously declared here
   13 |             for(int j=0;j<W;j++){
      |                     ^
a.cc:14:27: error: 'inp' was not declared in this scope; did you mean 'int'?
   14 |                 A[i,j] = (inp[j]=='#')?1:0;
      |                           ^~~
      |                           int
a.cc:14:31: error: use of 'j' before deduction of 'auto'
   14 |                 A[i,j] = (inp[j]=='#')?1:0;
      |                               ^
a.cc:17:9: error: 'Func' was not declared in this scope
   17 |         Func<int, int, bool> f = null;
      |         ^~~~
a.cc:17:14: error: expected primary-expression before 'int'
   17 |         Func<int, int, bool> f = null;
      |              ^~~
a.cc:18:9: error: 'f' was not declared in this scope
   18 |         f = (x, y) =>{
      |         ^
a.cc:18:14: error: 'x' was not declared in this scope
   18 |         f = (x, y) =>{
      |              ^
a.cc:18:17: error: 'y' was not declared in this scope
   18 |         f = (x, y) =>{
      |                 ^
a.cc:18:21: error: expected primary-expression before '>' token
   18 |         f = (x, y) =>{
      |                     ^
a.cc:18:22: error: expected primary-expression before '{' token
   18 |         f = (x, y) =>{
      |                      ^
a.cc:31:13: error: 'Console' was not declared in this scope
   31 |             Console.WriteLine("Possible");
      |             ^~~~~~~
a.cc:33:13: error: 'Console' was not declared in this scope
   33 |             Console.WriteLine("Impossible");
      |             ^~~~~~~
a.cc: At global scope:
a.cc:41:22: error: 'string' has not been declared
   41 |     static void Main(string[] args){
      |                      ^~~~~~
a.cc:41:31: error: expected ',' or '...' before 'args'
   41 |     static void Main(string[] args){
      |                               ^~~~
a.cc:45:2: error: expected ';' after class definition
   45 | }
      |  ^
      |  ;
a.cc: In static member function 'static void Program::Main(int*)':
a.cc:42:15: error: conversion from 'A*' to non-scalar type 'A' requested
   42 |         A a = new A();
      |               ^~~~~~~