Language: C++

#include <bits/stdc++.h>
using namespace std;
#define INF 1001000100010001000
#define MOD 1000000007
#define EPS 1e-10
#define int long long
#define rep(i, N) for (int i = 0; i < N; i++)
#define Rep(i, N) for (int i = 1; i < N; i++)
#define For(i, a, b) for (int i = (a); i < (b); i++)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define i_i pair<int, int>
#define vi vector<int>
#define vvi vector<vi >
#define vb vector<bool>
#define vvb vector<vb >
#define vp vector< i_i >
#define all(a) (a).begin(), (a).end()
#define Int(x) int x; cin >> x;
#define int2(x, y) Int(x); Int(y);
#define int3(x, y, z) Int(x); int2(y, z);
#define fir first
#define sec second
#define ffir first.first
#define fsec first.second
#define sfir second.first
#define ssec second.second
#define Decimal fixed << setprecision(10)

     

    //int dxy[5] = {0, 1, 0, -1, 0};

    // cmd${0:#:TARGET}

    

    signed main()

    {

        std::ios::sync_with_stdio(false);

        std::cin.tie(0);

int2(a, b);
vector<string> ans(0);

rep(i, 20) {
string up="", down="";
rep(j, 50){ if(a>1){
up += ".#";
down += "##";
a--;
}else{
up += "##";
down += "##";
} }
ans.pb(up); ans.pb(down);
if(a==1) break;
}

rep(i, 20) {
string up="", down="";
rep(j, 50){ if(b>1){
up += "..";
down += "#.";
b--;
}else{
up += "..";
down += "..";
} }
ans.pb(up); ans.pb(down);
if(b==1) break;
}

cout << ans.size()<<" "<<ans[0].size()
<<endl;

rep(i, ans.size())cout<<ans[i]<<endl;

        return 0;

    }



Compiler output:
a.cc:31:1: error: extended character   is not valid in an identifier
   31 |      
      | ^
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
   33 |     //int dxy[5] = {0, 1, 0, -1, 0};
      | ^
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:33:1: error: extended character   is not valid in an identifier
a.cc:35:1: error: extended character   is not valid in an identifier
   35 |     // cmd${0:#:TARGET}
      | ^
a.cc:35:1: error: extended character   is not valid in an identifier
a.cc:35:1: error: extended character   is not valid in an identifier
a.cc:35:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
   37 |     
      | ^
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:37:1: error: extended character   is not valid in an identifier
a.cc:39:1: error: extended character   is not valid in an identifier
   39 |     signed main()
      | ^
a.cc:39:1: error: extended character   is not valid in an identifier
a.cc:39:1: error: extended character   is not valid in an identifier
a.cc:39:1: error: extended character   is not valid in an identifier
a.cc:41:1: error: extended character   is not valid in an identifier
   41 |     {
      | ^
a.cc:41:1: error: extended character   is not valid in an identifier
a.cc:41:1: error: extended character   is not valid in an identifier
a.cc:41:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
   43 |         std::ios::sync_with_stdio(false);
      | ^
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:43:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
   45 |         std::cin.tie(0);
      | ^
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:45:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
   83 |         return 0;
      | ^
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:83:1: error: extended character   is not valid in an identifier
a.cc:85:1: error: extended character   is not valid in an identifier
   85 |     }
      | ^
a.cc:85:1: error: extended character   is not valid in an identifier
a.cc:85:1: error: extended character   is not valid in an identifier
a.cc:85:1: error: extended character   is not valid in an identifier
a.cc:31:1: error: '\U000000a0\U000000a0\U000000a0\U000000a0\U000000a0' does not name a type
   31 |      
      | ^~~~~