#include<stdio.h>
#define H 250

int h;

void print(int A[]){
  int i;

  for(i=1;i<=h;i++){
    printf("node %d: key = %d, ",i,A[i]);
    
    if(i != 1)  printf("parent key = %d, ",A[i/2]);

    if(i*2<=h) printf("left key = %d, ",A[i*2]);
    if(i*2+1<=h) printf("right key = %d, ",A[i*2+1]);

    printf("\n");
  }
}

int main(){

  int i,j;
  int A[H];

  scanf("%d",&h);

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

  print(A);

  return 0;
}

