#include<stdio.h>

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 H, i;
  int A[200000];
  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;
}