#include #define syosu(x) fixed< P; typedef pair pdd; typedef pair pll; typedef vector vi; typedef vector vvi; typedef vector vd; typedef vector vvd; typedef vector vl; typedef vector vvl; typedef vector vs; typedef vector

vp; typedef vector vvp; typedef vector vpll; typedef pair pip; typedef vector vip; const int inf=1<<30; const ll INF=1ll<<60; const double pi=acos(-1); const double eps=1e-8; const ll mod=1e9+7; const int dx[4]={-1,0,1,0},dy[4]={0,-1,0,1}; class Segment_Tree{ private: int n; vi date; int Rec(int a,int b,int k,int l,int r){ if(r<=a||b<=l) return 0; if(a<=l&&r<=b) return date[k]; int m=(l+r)/2; return Rec(a,b,k*2+1,l,m)+Rec(a,b,k*2+2,m,r); } public: Segment_Tree(int n_){ n=1; while(n0){ k=(k-1)/2; date[k]=date[k*2+1]+date[k*2+2]; } } int Query(int a,int b){ return Rec(a,b,0,0,n); } int Open(int k){ return date[k+n-1]; } }; int n; vi a; int main(){ cin>>n; a=vi(n); for(int i=0;i>a[i]; Segment_Tree st(n); ll t=0; for(int i=n-1;i>=0;i--){ a[i]--; t+=st.Query(0,a[i]); st.Update(a[i],1); } for(int i=0;i