foo.cc: In function 'int main()':
foo.cc:29:10: error: 'scanf' was not declared in this scope
   29 |   while (scanf("%d", &x)==1) a[++n]=x;
      |          ^~~~~
foo.cc:32:3: error: 'printf' was not declared in this scope
   32 |   printf("%d\n", best);
      |   ^~~~~~
foo.cc:3:1: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
    2 | #include <algorithm>
  +++ |+#include <cstdio>
    3 | using namespace std;

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