/in/foo.c: In function 'main':
/in/foo.c:5:2: error: 'amount' undeclared (first use in this function)
  amount = sys.stdin.readline().strip()
  ^~~~~~
/in/foo.c:5:2: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:5:11: error: 'sys' undeclared (first use in this function)
  amount = sys.stdin.readline().strip()
           ^~~
/in/foo.c:6:5: error: expected ';' before 'fee'
     fee=(amount-2000)*0.1
     ^~~