Language: C++

#include<iostream>
int main(){
	int w,n,a[30][2],b[30];
	std::cin>>w
		>>n;
	for(int i=0;i<n;++i){
			std::cin>>a[i][0]>>','>>a[i][1];
	}
	for(int i=1;i<=w;++i){
		b[i]=i;
	}
	for(int i=0;i<n;++i){
			int x=b[a[i][0]];
			b[a[i][0]]=b[a[i][1]];
			b[a[i][1]]=x;
	}
	for(int i=1;i<=w;++i){
		std::cout<<b[i]<<std::endl;
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:42: error: no match for 'operator>>' (operand types are 'std::basic_istream<char>::__istream_type' {aka 'std::basic_istream<char>'} and 'char')
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                         ~~~~~~~~~~~~~~~~~^~~~~
      |                                 |          |
      |                                 |          char
      |                                 std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/14/iostream:42,
                 from a.cc:1:
/usr/include/c++/14/istream:170:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  170 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:170:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:174:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  174 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:174:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'short int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:177:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  177 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:177:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'short unsigned int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:181:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  181 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/14/istream:181:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:184:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  184 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:184:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'unsigned int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:188:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  188 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:188:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'long int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:192:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  192 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:192:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'long unsigned int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:199:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'long long int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:203:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  203 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/14/istream:203:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'long long unsigned int&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:219:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  219 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:219:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'float&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:223:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  223 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:223:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'double&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:227:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  227 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/14/istream:227:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: cannot bind non-const lvalue reference of type 'long double&' to a value of type 'char'
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
/usr/include/c++/14/istream:328:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  328 |       operator>>(void*& __p)
      |       ^~~~~~~~
/usr/include/c++/14/istream:328:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: invalid conversion from 'char' to 'void*' [-fpermissive]
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
      |                                            |
      |                                            char
a.cc:7:44: error: cannot bind rvalue '(void*)44' to 'void*&'
/usr/include/c++/14/istream:122:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  122 |       operator>>(__istream_type& (*__pf)(__istream_type&))
      |       ^~~~~~~~
/usr/include/c++/14/istream:122:7: note:   conversion of argument 1 would be ill-formed:
a.cc:7:44: error: invalid conversion from 'char' to 'std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&)' {aka 'std::basic_istream<char>& (*)(std::basic_istream<char>&)'} [-fpermissive]
    7 |                         std::cin>>a[i][0]>>','>>a[i][1];
      |                                            ^~~
      |                                            |
      |                                            char
/usr/include/c++/14/istream:126:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_Cha