foo.cc: In function 'void mul(int*, int*, int*, int, int)':
foo.cc:42:6: warning: unused variable 'jw' [-Wunused-variable]
   42 |  int jw=0,i;
      |      ^~
foo.cc: In function 'int main()':
foo.cc:7:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    7 |  scanf("%d %d",&x1,&n1);
      |  ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:8:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    8 |  scanf("%d %d",&x2,&n2);
      |  ~~~~~^~~~~~~~~~~~~~~~~

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