#include<stdio.h>
#define MAX 100000

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,A[MAX+1];
  int i;
  
  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(A[parent(i)] != 0) printf("parent key = %d, ",A[parent(i)]);
    if(A[left(i)] != 0) printf("left key = %d, ",A[left(i)]);
    if(A[right(i)] != 0) printf("right key = %d, ",A[right(i)]);
    printf("\n");
  }
  
  return 0;
}

