#include <stdio.h>
#define MAX 251

int A[MAX];

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,H;
  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(i==1) printf("left key = %d, right key = %d\n",A[left(i)],A[right(i)]);
    else{
      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;
}