#include<stdio.h>

#define MAX 1000000

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;
}

