/in/foo.cc: In function 'int main()':
/in/foo.cc:8:2: error: expected ',' or ';' before 'for'
  for(int i=0; i<n; i++)
  ^~~
/in/foo.cc:8:15: error: 'i' was not declared in this scope
  for(int i=0; i<n; i++)
               ^
/in/foo.cc:7:6: warning: unused variable 'x' [-Wunused-variable]
  int x=0
      ^