/in/foo.cc: In function 'int main()':
/in/foo.cc:9:21: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
  while(scanf("%d",&n)==1){
                     ^
/in/foo.cc:11:42: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
   for(int i=1;i<=n;i++) {scanf("%d",&a[i]);a[i]+=maxn/2;}
                                          ^
/in/foo.cc:13:20: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
   printf("%d\n",ans);
                    ^