foo.cc: In function 'void solve()':
foo.cc:33:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |     scanf("%d%d", &m, &n);
      |     ~~~~~^~~~~~~~~~~~~~~~
foo.cc:35:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |         scanf("%s", mp[i]);
      |         ~~~~~^~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:53:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   53 |     freopen("data.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
foo.cc:56:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   56 |     if (multi) scanf("%d", &_);
      |                ~~~~~^~~~~~~~~~

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