#include<stdio.h>
#define MAX 100001

int main(){
  int i,n,H[MAX];

  scanf("%d",&n);

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

  for(i = 1; i <= n; i++){
    printf("node %d: key = %d, ",i,H[i]);
    if(i/2 >= 1){
      printf("parent key = %d, ",H[i/2]);
    }
    if(2*i <= n){
      printf("left key = %d, ",H[2*i]);
    }
    if(2*i+1 <= n){
      printf("right key = %d, ",H[2*i+1]);
    }
    printf("\n");
  }

  return 0;
}