#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
const int N=1e5+10;
int p[N],tree[N];
void creat(int node,int start,int end)
{
    if(start==end)  tree[node]=p[start];
    int mid=(start+end)/2;
    int left=node*2;
    int right=node*2+1;
    creat(left,start,mid);
    creat(right,mid+1,end);
    tree[node]=tree[right]+tree[left];
}
void update(int node,int start,int end,int x,int val)
{
    if(start==end)
    {
        p[x]=val;
        tree[node]=val;
    }
    int mid=(start+end)/2;
    int left=node*2;
    int right=node*2+1;
    if(x>=start&&x<=mid) update(left,start,mid,x,val);  
    else update(right,mid+1,end,x,val);
    tree[node]=tree[right]+tree[left];
}
int query(int node,int start,int end,int L,int R)
{
    if(start>R||end<L) return 0;
    else if(start>=L&&end<=R) return tree[node];
    else{
        int mid=(end+start)/2;
        int right=node*2+1;
        int left=node*2;
        int sum_left=query(left,start,mid,L,R);
        int sum_right=query(right,mid+1,end,L,R;)
        return sum_left+sum_right;
    }

}
int main ()
{
    int n;
    scanf("%d",&n);
    for(int i=0;i<=n;i++) cin>>p[i];
    creat(1,1,n);

    return 0;
}