#include<stdio.h>
#define	H 250

int parent(int);
int left(int);
int right(int);

int main()
{
  int n,i;
  int A[H];

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

  for(i = 1;i <= n;i++){
    printf("node %d: key = %d,",i,A[i]);
    if(parent(i) > 0) printf("parent key = %d,",A[parent(i)]);
    if(left(i) <= n) printf("left key = %d,",A[left(i)]);
    if(right(i) <= n) printf("right key = %d,",A[right(i)]);
    printf("\n");
  }

  return 0;
}

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

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

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