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

  return 0;
}

