#include <stdio.h>

#define MAX_H 250

int parent(int i) {return i / 2;}
int left(int i) {return 2 * i;}
int right(int i) {return 2 * i + 1;}

int main(void) {
	int H, i, A[MAX_H+1] = {0};
	
	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;
}