Language: C++

#include <iostream>
using namespace std;

int main() {
???int H, W;
???while (1) {
??????cin >> H >> W;
??????if (H == 0 && W == 0)break;
??????else {
?????????for (int i = 0; i < H; i++) {
????????????for (int j = 0; j < W; j++) {
???????????????printf("#");
????????????}
????????????printf("\n");
?????????}
??????}

???}
???return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:1: error: expected primary-expression before '?' token
    5 | ???int H, W;
      | ^
a.cc:5:2: error: expected primary-expression before '?' token
    5 | ???int H, W;
      |  ^
a.cc:5:3: error: expected primary-expression before '?' token
    5 | ???int H, W;
      |   ^
a.cc:5:4: error: expected primary-expression before 'int'
    5 | ???int H, W;
      |    ^~~
a.cc:5:4: error: expected ':' before 'int'
    5 | ???int H, W;
      |    ^~~
      |    :
a.cc:5:4: error: expected primary-expression before 'int'
    5 | ???int H, W;
      |    ^~~
a.cc:5:4: error: expected ':' before 'int'
    5 | ???int H, W;
      |    ^~~
      |    :
a.cc:5:4: error: expected primary-expression before 'int'
    5 | ???int H, W;
      |    ^~~
a.cc:5:4: error: expected ':' before 'int'
    5 | ???int H, W;
      |    ^~~
      |    :
a.cc:5:4: error: expected primary-expression before 'int'
    5 | ???int H, W;
      |    ^~~
a.cc:6:1: error: expected primary-expression before '?' token
    6 | ???while (1) {
      | ^
a.cc:6:2: error: expected primary-expression before '?' token
    6 | ???while (1) {
      |  ^
a.cc:6:3: error: expected primary-expression before '?' token
    6 | ???while (1) {
      |   ^
a.cc:6:4: error: expected primary-expression before 'while'
    6 | ???while (1) {
      |    ^~~~~
a.cc:6:4: error: expected ':' before 'while'
    6 | ???while (1) {
      |    ^~~~~
      |    :
a.cc:6:4: error: expected primary-expression before 'while'
    6 | ???while (1) {
      |    ^~~~~
a.cc:6:4: error: expected ':' before 'while'
    6 | ???while (1) {
      |    ^~~~~
      |    :
a.cc:6:4: error: expected primary-expression before 'while'
    6 | ???while (1) {
      |    ^~~~~
a.cc:6:4: error: expected ':' before 'while'
    6 | ???while (1) {
      |    ^~~~~
      |    :
a.cc:6:4: error: expected primary-expression before 'while'
    6 | ???while (1) {
      |    ^~~~~
a.cc:19:1: error: expected primary-expression before '?' token
   19 | ???return 0;
      | ^
a.cc:19:2: error: expected primary-expression before '?' token
   19 | ???return 0;
      |  ^
a.cc:19:3: error: expected primary-expression before '?' token
   19 | ???return 0;
      |   ^
a.cc:19:4: error: expected primary-expression before 'return'
   19 | ???return 0;
      |    ^~~~~~
a.cc:19:4: error: expected ':' before 'return'
   19 | ???return 0;
      |    ^~~~~~
      |    :
a.cc:19:4: error: expected primary-expression before 'return'
   19 | ???return 0;
      |    ^~~~~~
a.cc:19:4: error: expected ':' before 'return'
   19 | ???return 0;
      |    ^~~~~~
      |    :
a.cc:19:4: error: expected primary-expression before 'return'
   19 | ???return 0;
      |    ^~~~~~
a.cc:19:4: error: expected ':' before 'return'
   19 | ???return 0;
      |    ^~~~~~
      |    :
a.cc:19:4: error: expected primary-expression before 'return'
   19 | ???return 0;
      |    ^~~~~~