
#include<stdio.h>
#include<stdlib.h>
int parent(int);
int left(int);
int right(int);
  
int main(){
  int i,n,*A;
  scanf("%d",&n);
    A = (int*)malloc(sizeof(int)*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) >= 1)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;
}