#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 n,i,A[MAX + 1];

  scanf("%d",&n);
  for(i = 1 ; i <= n ; i++){
    scanf("%d",&A[i]);
  }
  for(i = 1 ; i <= n ; i++){
    printf("node %d: ",i);
    printf("key = %d, ",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;
}

