#include<stdio.h>
#define MAX 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() {
    int H, i, A[MAX+1];

    scanf("%d", &H);
    for (i = 1; i < H+1; i++) scanf("%d", &A[i]);
    
    for (i=1; i < H+1; 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;
}