Language: C++

#include <iostream>
#include <string>

using namespace std;
int main(){
  int heisei = 0;
  string S;cin >> S;
    if (S.substr(6,1) > '4'){
    }else{
      if (S.substr(8,2) >= "30"){
        heisei = 1;
      }
    }
  if (heisei == 1){
    cout << "Heisei" << endl;
  }else{
    cout << "TBD" <<endl;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:23: error: no match for 'operator>' (operand types are 'std::__cxx11::basic_string<char>' and 'char')
    8 |     if (S.substr(6,1) > '4'){
      |         ~~~~~~~~~~~~~ ^ ~~~
      |                 |       |
      |                 |       char
      |                 std::__cxx11::basic_string<char>
In file included from /usr/include/c++/14/string:48,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_iterator.h:462:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  462 |     operator>(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:462:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/bits/stl_iterator.h:507:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  507 |     operator>(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:507:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/bits/stl_iterator.h:1714:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1714 |     operator>(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1714:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::move_iterator<_IteratorL>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/bits/stl_iterator.h:1774:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1774 |     operator>(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1774:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::move_iterator<_IteratorL>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1058:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator>(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1058 |     operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1058:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::pair<_T1, _T2>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:695:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  695 |     operator> (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:695:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/string_view:702:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  702 |     operator> (basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:702:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/string_view:710:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  710 |     operator> (__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:710:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'char'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/bits/basic_string.h:3915:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3915 |     operator>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3915:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'char'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/bits/basic_string.h:3929:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3929 |     operator>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3929:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   mismatched types 'const _CharT*' and 'char'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
/usr/include/c++/14/bits/basic_string.h:3942:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator>(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3942 |     operator>(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3942:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   mismatched types 'const _CharT*' and 'std::__cxx11::basic_string<char>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2619:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator>(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2619 |     operator>(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2619:5: note:   template argument deduction/substitution failed:
a.cc:8:25: note:   'std::__cxx11::basic_string<char>' is not derived from 'const std::tuple<_UTypes ...>'
    8 |     if (S.substr(6,1) > '4'){
      |                         ^~~