foo.cpp: In function 'int main()':
foo.cpp:39:30: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'std::__cxx11::string* {aka std::__cxx11::basic_string<char>*}' [-Wformat=]
   scanf("%s %d%d\n",&cm,&x,&y);
                              ^