#include<stdio.h>
#define H 250

int main(){
  int h,i,a;
  int A[H];
  
  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(i != 1){
      printf("parent key = %d, ",A[i / 2]);
      if(i * 2 > h) printf("\n");
    }
    if(i * 2 <= h){
      printf("left key = %d, ",A[i * 2]);
      if(i * 2 + 1 > h) printf("\n");
    }
    if(i * 2 + 1 <= h){
      printf("right key = %d, \n",A[i * 2 + 1]);
    }
    
  }
  return 0;
}

