#include <stdio.h>
#define H 251

int main()
{
	int i,n;
	int A[H];
	
	scanf("%d",&n);
	for(i=1;i<=n;i++){
		scanf("%d",&A[i]);
	}
	
	for(i=1;i<=n;i++){
		printf("node %d: key = %d, ",i,A[i]);
		
		if(i/2 != 0){
			printf("parent key = %d, ",A[i/2]);
		}
		
		if(2*i <= n){
			printf("left key = %d, ",A[2*i]);
		}
		
		if(2*i+1 <= n){
			printf("right key = %d, ",A[2*i+1]);
		}
		printf("\n");
	}
	return 0;
}