#include<stdio.h>
#define MAX 100001

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];
  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;
}