/in/foo.c: In function 'main':
/in/foo.c:9:2: error: expected ';' before 'scanf'
  scanf("%d",&n)
  ^~~~~
/in/foo.c:7:6: warning: unused variable 'sum' [-Wunused-variable]
  int sum = 0;
      ^~~
/in/foo.c:6:6: warning: unused variable 'j' [-Wunused-variable]
  int j = 1;
      ^
/in/foo.c:5:6: warning: unused variable 'i' [-Wunused-variable]
  int i = 1;
      ^