#include<stdio.h>
#define H 250
int main()
{
  int a,i,A[H];
  scanf("%d",&a);
  for(i=1;i<=a;i++){
    scanf("%d",&A[i]);
  }
  for(i=1;i<=a;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if(i/2>=1) printf("parent key = %d, ",A[i/2]);
    if(2*i<=a) printf("left key = %d, ",A[2*i]);
    if(2*i+1<=a) printf("right key = %d, ",A[2*i+1]);
    printf("\n");
  }
  return 0;
}

