View Compilation Error

0_0_35351489_2727.cpp: In function 'int main()':
0_0_35351489_2727.cpp:20:14: error: cannot convert 'std::string {aka std::basic_string<char>}' to 'char*' for argument '1' to 'char* gets(char*)'
  while(gets(s)!=NULL){
              ^