/in/foo.cc: In function 'int main()':
/in/foo.cc:10:22: error: 'a' was not declared in this scope
   10 |                 cin>>a[i];
      |                      ^
/in/foo.cc:12:14: error: 'a' was not declared in this scope
   12 |         sort(a.begin(),a.end());
      |              ^