foo.cc: In function 'int main()':
foo.cc:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |  scanf("%lld%lld%lld%lld", &n, &m, &a, &b);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:27:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   27 |   for (int j = 1; j <= m; j++) scanf("%lld", &g[i][j]);
      |                                ~~~~~^~~~~~~~~~~~~~~~~~

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