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

int parent(int);
int left(int);
int right(int);

int main(){
  int h,l,r,*A;
  int i;

  scanf("%d",&h);
  A = (int *)malloc(sizeof(int)*(h+1));
  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(i!=1) printf("parent key = %d, ",A[parent(i)]);
    if((l=left(i)) <= h) printf("left key = %d, ",A[l]);
    if((r=right(i)) <= h) printf("right key = %d, ",A[r]);
    printf("\n");
  }

  return 0;
}

int parent(int i){
  if(i%2==0) return i/2;
  else return (i-1)/2;
}

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

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