#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int parent(int i){
  return floor(i/2);
}

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

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

int main(int argc, char const *argv[]) {
  int count,i;
  int A[100000];

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