foo.cc: In function 'void i_be_bigi(int, bigint&)':
foo.cc:8:6: warning: unused variable 'i' [-Wunused-variable]
    8 |  int i;
      |      ^
foo.cc: In function 'void chu(bigint&, int, bigint&, int&)':
foo.cc:67:3: warning: 'qy' may be used uninitialized in this function [-Wmaybe-uninitialized]
   67 |  d=qy;
      |  ~^~~

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