#include <stdio.h>
#define N 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 i,h;
  int A[N+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;
}