#include<stdio.h>
#define MAX 250



int parent(int x){
  return x/2;
}

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

int left(int x){
  return x*2;
}


int main(){

  int H,i,a[MAX+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;
}

