foo.c: In function ‘main’:
foo.c:8:9: error: ‘cin’ undeclared (first use in this function)
    8 |         cin>>a>>b>>c;
      |         ^~~
foo.c:8:9: note: each undeclared identifier is reported only once for each function it appears in
foo.c:20:14: error: ‘c）’ undeclared (first use in this function)
   20 |         if(b>c）
      |              ^~~
foo.c:20:17: error: expected ‘)’ before ‘{’ token
   20 |         if(b>c）
      |           ~     ^
      |                 )
   21 | 
   22 |         {
      |         ~        
foo.c:30:1: error: expected expression before ‘}’ token
   30 | }
      | ^