#include<stdio.h>
#define MAX 100000
int parent(int i){return i/2;}
int left(int i){return 2*i;}
int right(int i){return 2*i+1;}

int main(){
	int H, i, A[MAX+1];
	scanf("%d",&H);
	for(i = 1;i <= H;i++){
		scanf("%d",&A[i]);
	}
	for(i = 1;i <= H;i++){
		printf("node %d: key = %d, ",i,A[i]);
		if(parent(i)>=1){
			printf("parent key = %d, ",A[parent(i)]);
		}
		if(left(i)<=H){
			printf("left key = %d, ",A[left(i)]);
		}
		if(right(i) <= H){
			printf("right key = %d, ",A[right(i)]);
			
		}
		printf("\n");
	}
	return 0;
}
