Main.c: In function ‘f’:
Main.c:16:31: error: stray ‘\342’ in program
   16 |   return f(x - 1) + (1 / 3) * ​f(x - 2) < (1 / 2) * f(x - 4) ?
      |                               ^
Main.c:16:32: error: stray ‘\200’ in program
   16 |   return f(x - 1) + (1 / 3) * ​f(x - 2) < (1 / 2) * f(x - 4) ?
      |                                ^
Main.c:16:33: error: stray ‘\213’ in program
   16 |   return f(x - 1) + (1 / 3) * ​f(x - 2) < (1 / 2) * f(x - 4) ?
      |                                 ^
Main.c:17:24: error: stray ‘\342’ in program
   17 |   f(x - 1) + (1 / 3) * ​f(x - 2) : (1 / 2) * f(x - 4);
      |                        ^
Main.c:17:25: error: stray ‘\200’ in program
   17 |   f(x - 1) + (1 / 3) * ​f(x - 2) : (1 / 2) * f(x - 4);
      |                         ^
Main.c:17:26: error: stray ‘\213’ in program
   17 |   f(x - 1) + (1 / 3) * ​f(x - 2) : (1 / 2) * f(x - 4);
      |                          ^
Main.c: In function ‘main’:
Main.c:23:2: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
   23 |  scanf("%lf", &x);
      |  ^~~~~~~~~~~~~~~~