Can't compile file:
program.cpp: In function 'std::string guess_sequence(int)':
program.cpp:10:23: error: 'press' was not declared in this scope
   10 |                 int z=press(ans+'A');
      |                       ^~~~~
program.cpp:11:31: warning: conversion from 'std::__cxx11::basic_string<char>::size_type' {aka 'long long unsigned int'} to 'int' may change value [-Wconversion]
   11 |                 int k=ans.size();
      |                       ~~~~~~~~^~
grader_judge.cpp: In function 'int press(std::string)':
grader_judge.cpp:20:19: warning: conversion from 'std::__cxx11::basic_string<char>::size_type' {aka 'long long unsigned int'} to 'int' may change value [-Wconversion]
   20 |   int M = p.length();
      |           ~~~~~~~~^~
grader_judge.cpp: In function 'int main(int, char**)':
grader_judge.cpp:46:14: warning: unused parameter 'argc' [-Wunused-parameter]
   46 | int main(int argc, char **argv) {
      |          ~~~~^~~~
grader_judge.cpp:46:27: warning: unused parameter 'argv' [-Wunused-parameter]
   46 | int main(int argc, char **argv) {
      |                    ~~~~~~~^~~~                   ~~~~~~~^~~~