foo.cc: In function 'int main()':
foo.cc:71:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   71 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:73:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   73 |   scanf("%d",&a[i]),b[i]=a[i];
      |   ~~~~~^~~~~~~~~~~~
foo.cc:76:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   76 |   scanf("%d%d",&x,&y);
      |   ~~~~~^~~~~~~~~~~~~~
foo.cc:88:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   88 |   scanf("%d%d",&x,&y);
      |   ~~~~~^~~~~~~~~~~~~~

Found 4 testcases.
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