/in/foo.cc: In function 'int main()':
/in/foo.cc:20:25: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'long long int' [-Wformat=]
           scanf("%lld",a);
                         ^
/in/foo.cc:20:26: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
           scanf("%lld",a);
                          ^