#include<stdio.h>

int main()
{
  int i,A[251],n;
  scanf("%d",&n);
  for(i=1;i<n+1;i++)
    {
      scanf("%d",&A[i]);
    }

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

  return 0;
}