#include <stdio.h>
#define H 250
#define NIL -1

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

int main(){
  
  int n = 0;
  int A[H];
  int i = 0;
  
  scanf("%d",&n);
  for(i = 1; i <= n; i++){//1-origin
    scanf("%d",&A[i]);
  }

  for(i = 1; i <= n; i++){
    printf("node %d: key = %d, ",i,A[i]);
    
    if(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 i*2;
}

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

