/in/foo.c: In function 'main':
/in/foo.c:5:3: error: expected declaration specifiers before 'for'
    5 |   for(i=100,i<1000,i++){
      |   ^~~
/in/foo.c:12:3: error: expected declaration specifiers before 'return'
   12 |   return 0;
      |   ^~~~~~
/in/foo.c:13:1: error: expected declaration specifiers before '}' token
   13 | }
      | ^
/in/foo.c:4:13: error: declaration for parameter 'c' but no such parameter
    4 |   int i,a,b,c;
      |             ^
/in/foo.c:4:11: error: declaration for parameter 'b' but no such parameter
    4 |   int i,a,b,c;
      |           ^
/in/foo.c:4:9: error: declaration for parameter 'a' but no such parameter
    4 |   int i,a,b,c;
      |         ^
/in/foo.c:4:7: error: declaration for parameter 'i' but no such parameter
    4 |   int i,a,b,c;
      |       ^
/in/foo.c:14: error: expected '{' at end of input