#include <stdio.h>

int main()
{
  int n,i;

  scanf("%d",&n);

  int A[n+1];

  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!=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;
}

