Language: C++

#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>
#include <utility>
#include <tuple>
#include <cmath>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vvi = vector<vi>;
using vs = vector<string>;
using vl = vector<ll>;
using vvl = vector<vl>;
using P = pair<int, int>;
using T = tuple<int, int, int>;
using vp = vector<P>;
struct initon
{
    initon()
    {
        cin.tie(0);
        ios::sync_with_stdio(false);
    };
};
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, m, n) for (i64 i = m; i < n; i++)
#define SORT(x) sort(x.begin(), x.end())
#define RS(x) rsort(x.begin(),x,end()))
#define REVE(x) reverse(x.begin(), x.end())
#define all(x) (x).begin(), (x).end()
#define fst first
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define pob pop_back
#define sw swap
#define UP(x) transform(x.begin(), x.end(), x.begin(), ::toupper);
#define LOW(x) transform(x.begin(), x.end(), x.begin(), ::tolower);
#define na(a, n) rep(i, n) cin >> a[i];
template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return 1;
    }
    return 0;
}
vb d(10);
int ans(int x)
{
    while (x)
    {
        if (d[x % 10])
            return 0;
        x /= 10;
    }
    return 1;
}
//ここからメイン
int main()
{
    char a,b;
cin>>a>>b;
cout <<a>=b?a==b?'=':'>':'<'
}

Compiler output:
a.cc: In function 'int main()':
a.cc:82:9: error: no match for 'operator>=' (operand types are 'std::basic_ostream<char>' and 'char')
   82 | cout <<a>=b?a==b?'=':'>':'<'
      | ~~~~~~~~^~~
      |      |    |
      |      |    char
      |      std::basic_ostream<char>
a.cc:82:9: note: candidate: 'operator>=(int, int)' (built-in)
   82 | cout <<a>=b?a==b?'=':'>':'<'
      | ~~~~~~~~^~~
a.cc:82:9: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'int'
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:476:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  476 |     operator>=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:476:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/bits/stl_iterator.h:520:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  520 |     operator>=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:520:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/bits/stl_iterator.h:1724:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator>=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1724 |     operator>=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1724:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/bits/stl_iterator.h:1781:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator>=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1781 |     operator>=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1781:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
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:1070:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator>=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1070 |     operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1070:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::pair<_T1, _T2>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
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:739:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>=(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  739 |     operator>=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:739:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/string_view:746:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>=(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  746 |     operator>=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:746:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/string_view:754:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator>=(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  754 |     operator>=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:754:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'char'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/bits/basic_string.h:3997:5: 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>&)'
 3997 |     operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3997:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/bits/basic_string.h:4011:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator>=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 4011 |     operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:4011:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
/usr/include/c++/14/bits/basic_string.h:4024:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator>=(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 4024 |     operator>=(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:4024:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
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:2631:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator>=(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2631 |     operator>=(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2631:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::tuple<_UTypes ...>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:3:
/usr/include/c++/14/bits/stl_vector.h:2114:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator>=(const vector<_Tp, _Alloc>&, const vector<_Tp, _Alloc>&)'
 2114 |     operator>=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_vector.h:2114:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::vector<_Tp, _Alloc>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
In file included from /usr/include/c++/14/map:63,
                 from a.cc:4:
/usr/include/c++/14/bits/stl_map.h:1578:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator>=(const map<_Key, _Tp, _Compare, _Allocator>&, const map<_Key, _Tp, _Compare, _Allocator>&)'
 1578 |     operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_map.h:1578:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::map<_Key, _Tp, _Compare, _Allocator>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
In file included from /usr/include/c++/14/map:64:
/usr/include/c++/14/bits/stl_multimap.h:1200:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator>=(const multimap<_Key, _Tp, _Compare, _Allocator>&, const multimap<_Key, _Tp, _Compare, _Allocator>&)'
 1200 |     operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_multimap.h:1200:5: note:   template argument deduction/substitution failed:
a.cc:82:11: note:   'std::basic_ostream<char>' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Allocator>'
   82 | cout <<a>=b?a==b?'=':'>':'<'
      |           ^
In file included from /usr/include/c++/14/deque:66,
                 from /usr/include/c++/14/queue:62,
                 from a.cc:6:
/usr/include/c++/14/bits/stl_deque.h:2363:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator>=(const deque<_Tp, _Alloc>&, const deque<_Tp, _Alloc>&)'
 2363 |     operator>=(co