#include<stdio.h>

#define MAX 5000

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

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

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

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

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

