foo.cc: In function 'int main()':
foo.cc:14:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i=1;i<=n;i++)
  ^~~
foo.cc:26:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   printf("%d",res);
   ^~~~~~
foo.cc:7:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:11:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
        scanf("%d",&a[i]);
        ~~~~~^~~~~~~~~~~~

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