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

  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;
	       
}