foo.cc: In function 'void solve()':
foo.cc:29:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   29 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
foo.cc:32:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   32 |         scanf("%d", &a), s[a].emplace_back(i);
      |         ~~~~~^~~~~~~~~~
foo.cc:34:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   34 |         scanf("%d", &x[i]);
      |         ~~~~~^~~~~~~~~~~~~

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