#include<stdio.h>

#define H 250

int main(){
  int A[H], n;

  scanf("%d",&n);
  for(int i = 1; i <= n; i++){
    scanf("%d",&A[i]);
  }

  for(int i = 1; i <= n; i++){
    printf("node %d: ",i);
    printf("key = %d, ",A[i]);
    if(i != 1 && 2*i <= n) printf("parent key = %d, ",A[i/2]);
    if(i != 1 && 2*i+1 > n && 2*i > n) printf("parent key = %d, \n",A[i/2]);
    if(2*i <= n && 2*i+1 <= n) printf("left key = %d, ",A[2*i]);
    if(2*i <= n && 2*i+1 > n) printf("left key = %d, \n",A[2*i]);
    if(2*i+1 <= n) printf("right key = %d, \n",A[2*i+1]);
  }
  
  return 0;
}

