#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;
}

