#include<stdio.h>
#define H 250

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 i,n;
  int A[H+1];

  scanf("%d",&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(i/2>=1)
      printf("parent key = %d, ",A[parent(i)]);      
    if(2*i<=n)
      printf("left key = %d, ",A[left(i)]);
    if(2*i+1<=n)
      printf("right key = %d, ",A[right(i)]);
  printf("\n");    
  }



  return 0;
}