Language: C++

#include<iostream>
using namespace std;

void change(int a, int b);

int main(){
	int a, b, c, t;
	cin >> a >> b >> c;

	if(a > b){
		change(a, b);
	}

	if(a > c){
		change(a, b);
	}

	if(b > c){
		change(b, c);
	}

	cout << a << ??? ??? << b << ??? ??? << c ;

	return 0;
}

void change(int a, int b){
	int t;

	t = a;
	a = b;
	b = t;

	return;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:22:22: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                      ^
a.cc:22:23: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                       ^
a.cc:22:24: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                        ^
a.cc:22:26: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                          ^
a.cc:22:27: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                           ^
a.cc:22:28: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                            ^
a.cc:22:30: error: expected primary-expression before '<<' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                              ^~
a.cc:22:38: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                      ^
a.cc:22:39: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                       ^
a.cc:22:40: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                        ^
a.cc:22:42: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                          ^
a.cc:22:43: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                           ^
a.cc:22:44: error: expected primary-expression before '?' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                            ^
a.cc:22:46: error: expected primary-expression before '<<' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                              ^~
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^
a.cc:22:50: error: expected ':' before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                  ^~
      |                                                  :
a.cc:22:51: error: expected primary-expression before ';' token
   22 |         cout << a << ??? ??? << b << ??? ??? << c ;
      |                                                   ^