foo.cc: In function 'int main()':
foo.cc:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~~
foo.cc:17:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&c[i][j]);
     ~~~~~^~~~~~~~~~~~~~~
foo.cc:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d%d",&s.x,&s.y,&t.x,&t.y);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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