#include<stdio.h>

int main(){
  int i,n,key[251];

  scanf("%d",&n);

  for(i=1;i<=n;i++){
    scanf("%d",&key[i]);
  }

  for(i=1;i<=n;i++){

    printf("node %d: key = %d, ",i,key[i]);

    if(i>1){
      printf("parent key = %d, ",key[i/2]);
    }

    if(2*i<=n){
      printf("left key = %d, ",key[2*i]);
    }

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

    printf("\n");
  }
  return 0;
}