/in/foo.cc: In function 'bool judge(int)':
/in/foo.cc:44:12: warning: unused variable 'j' [-Wunused-variable]
   44 |     int i, j, z;
      |            ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:58:10: warning: unused variable 'ch' [-Wunused-variable]
   58 |     char ch;
      |          ^~