#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 A[MAX+1], H, 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(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;
}

