#include<stdio.h>
#define M 10000

int parent(int n){
  return n/2;
}
int left(int n){
  return n*2;
}
int right(int n){
  return n*2+1;
}

int main(){
  int A[M+1];
  int h;
  int i;
  
  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;
}

