#include<stdio.h>
#define N 10000

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

int main(){  
  int H,i,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;
}


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

