foo.c: In function 'main':
foo.c:28:5: warning: statement with no effect [-Wunused-value]
   28 |   b1+b2;
      |   ~~^~~
foo.c:25:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   25 |  scanf("%d%d\n",&b1,&a1);
      |  ^~~~~~~~~~~~~~~~~~~~~~~
foo.c:26:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   26 |  scanf("%d%d",&b2,&a2);
      |  ^~~~~~~~~~~~~~~~~~~~~
foo.c:36:3: warning: 'k1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   36 |  m=sum/gy(sum,k1);
      |  ~^~~~~~~~~~~~~~~

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