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

#define MAX 100000

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;
  int i;
  int 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;
}

