#include<stdio.h>
 
int main()
{
  int i,A[251],n;
  
  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!=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;
}