#include<stdio.h>

#define MAX 250

int main(){

  int id,key,i,A[MAX];

  scanf("%d",&id);

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

  for(i = 1; i <= id; i++){
    printf("node %d: key = %d, ",i,A[i]);

    if(i != 1) printf("parent key = %d, ",A[i/2]);

    if(2*i <= id) printf("left key = %d, ",A[2*i]);
    else {
      printf("\n");
      continue;
    }
    if(2*i+1 <= id) printf("right key = %d, \n",A[2*i+1]);
    else printf("\n");
  }
  return 0;
}