/in/foo.cc: In function 'int main()':
/in/foo.cc:8:2: error: expected ',' or ';' before 'for'
  for(int i=a;i<=n;i++)
  ^~~
/in/foo.cc:8:14: error: 'i' was not declared in this scope
  for(int i=a;i<=n;i++)
              ^