View Compilation Error

0_0_17327643_7785.cpp: In function 'int main()':
0_0_17327643_7785.cpp:16:6: error: 'class std::stack<char>' has no member named 'clear'
   st.clear();
      ^
0_0_17327643_7785.cpp:17:5: error: 'class std::queue<std::basic_string<char> >' has no member named 'clear'
   q.clear();
     ^