#include<stdio.h>
#include<stdlib.h>

int main(){

  int i,n,a[250];


  scanf("%d",&n);

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

    scanf("%d",&a[i]);
  }

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

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

    if(i/2 <= n && i/2 > 0)
      printf("parent key = %d, ", a[i/2]);

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

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

    printf("\n");
  }


  return 0;
}

      
      

