foo.cc: In function 'int main()':
foo.cc:5:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    5 | scanf("%d%d",&n,&m);
      | ~~~~~^~~~~~~~~~~~~~
foo.cc:8:4: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
    8 | ans+=max(0,(n-i+1)*(m-i+1));
      | ~~~^~~~~~~~~~~~~~~~~~~~~~~~

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