foo.cc: In function 'int main(int, char**)':
foo.cc:13:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&y,&x);
  ~~~~~^~~~~~~~~~~~~~
foo.cc: In function 'void Input(int (*)[502], int, int, int, int)':
foo.cc:43:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a[j][i]);
    ~~~~~^~~~~~~~~~~~~~~

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