#include<stdio.h>
#define NUM 100001

int parent(int a){
  return a/2;
}

int left(int a){
  return 2*a;
}

int right(int a){
  return 2*a+1;
}

int main(){
  int n,i,A[NUM];

  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) > 0)
      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;
}