/in/foo.cc: In function 'int main()':
/in/foo.cc:36:23: warning: format '%u' expects argument of type 'unsigned int*', but argument 2 has type 'ull* {aka long long unsigned int*}' [-Wformat=]
    scanf("%I64u",&a[i]);
                       ^
/in/foo.cc:60:40: warning: format '%u' expects argument of type 'unsigned int', but argument 3 has type 'ull {aka long long unsigned int}' [-Wformat=]
    printf("Case #%d: %I64u\n",sum-t,ans);
                                        ^