Language: C++

#include <iostream>
using namespace std;

int main(){
	int b[4][13]={0},m;
	for(int i = 0; i < m; i++){
		cin >> x;
		cin >> n;
		if(x=='S'){
			b[0][n]=1;
		}
		else if(x=='H'){
			b[1][n]=1;
		}
		else if(x=='C'){
			b[2][n]=1;
		}
		else if(x=='D'){
			b[3][n]=1;
		}
	}
		for(int l = 0; l < 13; l++){
			if(b[0][l]==0){
				cout << "S" << " " << l << "n\"
			}
		}
		for(int l = 0; l < 13; l++){
			if(b[1][l]==0){
				cout << "H" << " " << l << "n\"
			}
		}for(int l = 0; l < 13; l++){
			if(b[2][l]==0){
				cout << "C" << " " << l << "n\"
			}
		}for(int l = 0; l < 13; l++){
			if(b[3][l]==0){
				cout << "D" << " " << l << "n\"
			}
		}



	}
	cout << a[0];
	cout << "\n";

	return 0;
}

Compiler output:
a.cc:24:60: warning: missing terminating " character
   24 |                                 cout << "S" << " " << l << "n\"
      |                                                            ^
a.cc:24:60: error: missing terminating " character
   24 |                                 cout << "S" << " " << l << "n\"
      |                                                            ^~~~
a.cc:29:60: warning: missing terminating " character
   29 |                                 cout << "H" << " " << l << "n\"
      |                                                            ^
a.cc:29:60: error: missing terminating " character
   29 |                                 cout << "H" << " " << l << "n\"
      |                                                            ^~~~
a.cc:33:60: warning: missing terminating " character
   33 |                                 cout << "C" << " " << l << "n\"
      |                                                            ^
a.cc:33:60: error: missing terminating " character
   33 |                                 cout << "C" << " " << l << "n\"
      |                                                            ^~~~
a.cc:37:60: warning: missing terminating " character
   37 |                                 cout << "D" << " " << l << "n\"
      |                                                            ^
a.cc:37:60: error: missing terminating " character
   37 |                                 cout << "D" << " " << l << "n\"
      |                                                            ^~~~
a.cc: In function 'int main()':
a.cc:7:24: error: 'x' was not declared in this scope
    7 |                 cin >> x;
      |                        ^
a.cc:8:24: error: 'n' was not declared in this scope
    8 |                 cin >> n;
      |                        ^
a.cc:25:25: error: expected primary-expression before '}' token
   25 |                         }
      |                         ^
a.cc:30:25: error: expected primary-expression before '}' token
   30 |                         }
      |                         ^
a.cc:34:25: error: expected primary-expression before '}' token
   34 |                         }
      |                         ^
a.cc:38:25: error: expected primary-expression before '}' token
   38 |                         }
      |                         ^
a.cc: At global scope:
a.cc:44:9: error: 'cout' does not name a type
   44 |         cout << a[0];
      |         ^~~~
a.cc:45:9: error: 'cout' does not name a type
   45 |         cout << "\n";
      |         ^~~~
a.cc:47:9: error: expected unqualified-id before 'return'
   47 |         return 0;
      |         ^~~~~~
a.cc:48:1: error: expected declaration before '}' token
   48 | }
      | ^