foo.cc: In function 'int main()':
foo.cc:8:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    8 |  scanf("%lld%lld%lld%lld", &n, &s, &a, &b);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Found 10 testcases.
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