1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. #define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  5. #define endl "\n"
  6. #define int long long
  7.  
  8. #define db(...) ZZ(#__VA_ARGS__, __VA_ARGS__)
  9. template <typename Arg1> void ZZ(const char* name, Arg1&& arg1){std::cerr << name << " = " << arg1 << endl;}
  10. template <typename Arg1, typename... Args>void ZZ(const char* names, Arg1&& arg1, Args&&... args)
  11. {
  12. 	const char* comma = strchr(names + 1, ',');
  13. 	std::cerr.write(names, comma - names) << " = " << arg1;
  14. 	ZZ(comma, args...);
  15. }
  16.  
  17. int32_t main()
  18. {
  19. 	IOS;
  20. 	for(int i=1;i<=2;i++)
  21. 	{
  22. 		for(int j=1;j<=2;j++)
  23. 		{
  24. 			for(char ch='a';ch<='b';ch++)
  25. 			{
  26. 				db(i);
  27. 				db(i, j);
  28. 				db(i, j, ch);
  29. 			}
  30. 		}
  31. 	}
  32. 	return 0;
  33. }
  34.  
  35. /* Output:
  36. i = 1
  37. i = 1, j = 1
  38. i = 1, j = 1, ch = a
  39. i = 1
  40. i = 1, j = 1
  41. i = 1, j = 1, ch = b
  42. i = 1
  43. i = 1, j = 2
  44. i = 1, j = 2, ch = a
  45. i = 1
  46. i = 1, j = 2
  47. i = 1, j = 2, ch = b
  48. i = 2
  49. i = 2, j = 1
  50. i = 2, j = 1, ch = a
  51. i = 2
  52. i = 2, j = 1
  53. i = 2, j = 1, ch = b
  54. i = 2
  55. i = 2, j = 2
  56. i = 2, j = 2, ch = a
  57. i = 2
  58. i = 2, j = 2
  59. i = 2, j = 2, ch = b
  60. */