/in/foo.c:3:9: error: expected ';' before 'int'
    3 | double m
      |         ^
      |         ;
    4 | int main(){
      | ~~~      
/in/foo.c: In function 'main':
/in/foo.c:5:5: error: 'cin' undeclared (first use in this function)
    5 |     cin>>m;
      |     ^~~
/in/foo.c:5:5: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:5:10: error: 'm' undeclared (first use in this function)
    5 |     cin>>m;
      |          ^
/in/foo.c:7:6: error: 'cout' undeclared (first use in this function)
    7 |     {cout <<m; endl
      |      ^~~~
/in/foo.c:7:16: error: 'endl' undeclared (first use in this function)
    7 |     {cout <<m; endl
      |                ^~~~
/in/foo.c:7:20: error: expected ';' before '}' token
    7 |     {cout <<m; endl
      |                    ^
      |                    ;
    8 |         /* code */
    9 |     }
      |     ~               
/in/foo.c:10:18: error: expected expression before '<' token
   10 |     else if (500=<m<1000)
      |                  ^
/in/foo.c:14:19: error: expected expression before '<' token
   14 |     else if (1000=<m<1500)
      |                   ^
/in/foo.c:15:18: error: expected ';' before '}' token
   15 |     {cout <<m*0.9
      |                  ^
      |                  ;
   16 |     }
      |     ~             
/in/foo.c:17:19: error: expected expression before '<' token
   17 |     else if (1500=<m<2000)
      |                   ^
/in/foo.c:24:13: error: expected ';' before '}' token
   24 |     return 0
      |             ^
      |             ;
   25 | }
      | ~