/in/foo.cc: In function 'int main()':
/in/foo.cc:236:4: error: no match for 'operator/=' (operand types are 'bigint' and 'int')
   m/=2;
   ~^~~
/in/foo.cc:202:9: note: candidate: bigint bigint::operator/=(bigint)
  bigint operator /= (bigint b)
         ^~~~~~~~
/in/foo.cc:202:9: note:   no known conversion for argument 1 from 'int' to 'bigint'