#include<stdio.h>
#define MAX 251

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

int main(){
  int i;
  int n;
  int A[MAX];
  
  scanf("%d", &n);

  for(i=1;i<n+1;i++){ 
    scanf("%d", &A[i]);
   
  }
   
  for(i=1;i<n+1;i++){  
    printf("node %d: key = %d, ", i, A[i]);   
    if(parent(i)>=1)printf("parent key = %d, ", A[parent(i)]);
    if(left(i)<=n)printf("left key = %d, ", A[left(i)]);
    if(right(i)<=n)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;
}

