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

int main() 
{
  int *a;
  int n,i;
  
  scanf("%d",&n);
  a = (int*)malloc(sizeof(int)*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/2>0) 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;
}