Language: C++

#include <iostream>
#include <algorithm>
using namespace std;
int count ;
int R,G,B,N;
void DFS(int r,int g){
	int ta = r*R + g*G;
  	int b = (N - ta)/B;
  	if(ta + b*B == N){
    	count ++;
      	return;
    }
  	if(ta + b*B > N)return;
  	for(int rr = r +1;rr<=3000;rr++)
      for(int gg = g;gg<=3000;gg++){
      	DFS(rr,gg);
      }
}
int main(){
  	while(cin>>R>>G>>B>>N){
	count = 0;
      DFS(0,0);
      cout<<count<<endl;
    }
  return 0;
}

Compiler output:
a.cc: In function 'void DFS(int, int)':
a.cc:10:9: error: reference to 'count' is ambiguous
   10 |         count ++;
      |         ^~~~~
In file included from /usr/include/c++/14/algorithm:86,
                 from a.cc:2:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:101:1: note: candidates are: 'template<class _ExecutionPolicy, class _ForwardIterator, class _Tp> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, typename std::iterator_traits<_II>::difference_type> std::count(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, const _Tp&)'
  101 | count(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~~
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:4025:5: note:                 'template<class _IIter, class _Tp> typename std::iterator_traits< <template-parameter-1-1> >::difference_type std::count(_IIter, _IIter, const _Tp&)'
 4025 |     count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
      |     ^~~~~
a.cc:4:5: note:                 'int count'
    4 | int count ;
      |     ^~~~~
a.cc: In function 'int main()':
a.cc:21:9: error: reference to 'count' is ambiguous
   21 |         count = 0;
      |         ^~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:101:1: note: candidates are: 'template<class _ExecutionPolicy, class _ForwardIterator, class _Tp> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, typename std::iterator_traits<_II>::difference_type> std::count(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, const _Tp&)'
  101 | count(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~~
/usr/include/c++/14/bits/stl_algo.h:4025:5: note:                 'template<class _IIter, class _Tp> typename std::iterator_traits< <template-parameter-1-1> >::difference_type std::count(_IIter, _IIter, const _Tp&)'
 4025 |     count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
      |     ^~~~~
a.cc:4:5: note:                 'int count'
    4 | int count ;
      |     ^~~~~
a.cc:23:13: error: reference to 'count' is ambiguous
   23 |       cout<<count<<endl;
      |             ^~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:101:1: note: candidates are: 'template<class _ExecutionPolicy, class _ForwardIterator, class _Tp> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, typename std::iterator_traits<_II>::difference_type> std::count(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, const _Tp&)'
  101 | count(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~~
/usr/include/c++/14/bits/stl_algo.h:4025:5: note:                 'template<class _IIter, class _Tp> typename std::iterator_traits< <template-parameter-1-1> >::difference_type std::count(_IIter, _IIter, const _Tp&)'
 4025 |     count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
      |     ^~~~~
a.cc:4:5: note:                 'int count'
    4 | int count ;
      |     ^~~~~