foo.cc: In function 'void solve()':
foo.cc:11:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   11 |     scanf("%lld%lld%lld%lld%lld%lld", &n, &m, &q, &u, &v, &t);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:17:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   17 |     for (int i=1; i<=n; i++) scanf("%d", &ff[i]);
      |                              ~~~~~^~~~~~~~~~~~~~

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