#include <stdio.h>
#define MAX 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,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 : 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;
}




