#include <stdio.h>

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[251];
	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(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;
}
