foo.cc: In function 'int main()':
foo.cc:6:2: error: 'cin' was not declared in this scope
    6 |  cin>>n;
      |  ^~~
foo.cc:2:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
    1 | #include <cstdio>
  +++ |+#include <iostream>
    2 | using namespace std;
foo.cc:11:4: error: 'cout' was not declared in this scope
   11 |    cout<<"No"<<endl;
      |    ^~~~
foo.cc:11:4: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:11:16: error: 'endl' was not declared in this scope
   11 |    cout<<"No"<<endl;
      |                ^~~~
foo.cc:2:1: note: 'std::endl' is defined in header '<ostream>'; did you forget to '#include <ostream>'?
    1 | #include <cstdio>
  +++ |+#include <ostream>
    2 | using namespace std;
foo.cc:16:2: error: 'cout' was not declared in this scope
   16 |  cout<<"Yes";
      |  ^~~~
foo.cc:16:2: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:5:10: warning: unused variable 's' [-Wunused-variable]
    5 |  int n,i,s=0;
      |          ^

[Hydro](https://hydro.ac)提供评测服务