text3.cpp: In function 'int main()': text3.cpp:18: error: 'struct std::string' has no member named 'front' text3.cpp:19: warning: array subscript has type 'char' text3.cpp:20: warning: array subscript has type 'char' text3.cpp:21: error: 'struct std::string' has no member named 'back' text3.cpp:22: warning: array subscript has type 'char' text3.cpp:23: warning: array subscript has type 'char' text3.cpp:24: warning: array subscript has type 'char'