#include<stdio.h>
#include<stdlib.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,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;

}

