#include <stdio.h>
#define MAX 250

int main(){
  int h,i;
  int a[MAX+1];

  scanf("%d",&h);
  for(i=1;i<=h;i++){
    scanf("%d",&a[i]);
  }

  for(i=1;i<=h;i++){
    printf("node %d: key = %d, ",i,a[i]);
    if(i/2 >= 1) printf("parent key = %d, ",a[i/2]);
    if(i*2 <= h) printf("left key = %d, ",a[i*2]);
    if(i*2+1 <= h) printf("right key = %d, ",a[i*2+1]);
    printf("\n");
  }
  return 0;
}

