/in/foo.cc: In function 'int dfs(std::__cxx11::string, long long int)':
/in/foo.cc:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<str.size();i+=2)
              ~^~~~~~~~~~~
/in/foo.cc:21:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i<str.size()-1&&str[i]==str[i+1]){fg=0;break;}
      ~^~~~~~~~~~~~~
/in/foo.cc:23:40: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  if(fg)res+=dfs(nxt,str.size()&1?k>>1:k+1>>1);
                                       ~^~
/in/foo.cc:25:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<str.size();i+=2)
              ~^~~~~~~~~~~
/in/foo.cc:26:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i<str.size()-1&&str[i]==str[i+1]){fg=0;break;}
      ~^~~~~~~~~~~~~
/in/foo.cc:28:35: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  if(fg)res+=dfs(nxt,str.size()&1?k+1>>1:k>>1);
                                  ~^~