#include <stdio.h>
#define MAX 100000

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

