content: package data_structures.trees;
  
  import java.util.Scanner;
  
  // Range Sum Query (with lazy propagation)
  
  public class SegmentTree {		// 1-based DS, OOP
  	
  	int N; 			//the number of elements in the array as a power of 2 (i.e. after padding)
  	int[] array, sTree, lazy;
  	
  	SegmentTree(int[] in)		
  	{
  		array = in; N = in.length - 1;
  		sTree = new int[N<<1];		//no. of nodes = 2*N - 1, we add one to cross out index zero
  		lazy = new int[N<<1];
  		build(1,1,N);
  	}
  	
  	void build(int node, int b, int e)	// O(n)
  	{
  		if(b == e)					
  			sTree[node] = array[b];
  		else						
  		{
  			int mid = b + e >> 1;
  			build(node<<1,b,mid);
  			build(node<<1|1,mid+1,e);
  			sTree[node] = sTree[node<<1]+sTree[node<<1|1];
  		}
  	}
  	
  	
  	void update_point(int index, int val)			// O(log n)
  	{
  		index += N - 1;				
  		sTree[index] += val;			
  		while(index>1)				
  		{
  			index >>= 1;
  			sTree[index] = sTree[index<<1] + sTree[index<<1|1];		
  		}
  	}
  	
  	
  	void update_range(int i, int j, int val)		// O(log n) 
  	{
  		update_range(1,1,N,i,j,val);
  	}
  	
  	void update_range(int node, int b, int e, int i, int j, int val)
  	{
  		if(i > e || j < b)		
  			return;
  		if(b >= i && e <= j)		
  		{
  			sTree[node] += (e-b+1)*val;			
  			lazy[node] += val;				
  		}							
  		else		
  		{
  			int mid = b + e >> 1;
  			propagate(node, b, mid, e);
  			update_range(node<<1,b,mid,i,j,val);
  			update_range(node<<1|1,mid+1,e,i,j,val);
  			sTree[node] = sTree[node<<1] + sTree[node<<1|1];		
  		}
  		
  	}
  	void propagate(int node, int b, int mid, int e)		
  	{
  		lazy[node<<1] += lazy[node];
  		lazy[node<<1|1] += lazy[node];
  		sTree[node<<1] += (mid-b+1)*lazy[node];		
  		sTree[node<<1|1] += (e-mid)*lazy[node];		
  		lazy[node] = 0;
  	}
  	
  	int query(int i, int j)
  	{
  		return query(1,1,N,i,j);
  	}
  	
  	int query(int node, int b, int e, int i, int j)	// O(log n)
  	{
  		if(i>e || j <b)
  			return 0;		
  		if(b>= i && e <= j)
  			return sTree[node];
  		int mid = b + e >> 1;
  		propagate(node, b, mid, e);
  		int q1 = query(node<<1,b,mid,i,j);
  		int q2 = query(node<<1|1,mid+1,e,i,j);
  		return q1 + q2;	
  				
  	}
  	
  	
  	public static void main(String[] args) {
  		
  		Scanner sc = new Scanner(System.in);
  		
  		int n = sc.nextInt();
  		int N = 1; while(N < n) N <<= 1; //padding
  		
  		int[] in = new int[N + 1];
  		for(int i = 1; i <= n; i++)
  			in[i] = sc.nextInt();
  		
  		sc.close();
  	}
  	
  }
  