#include <stdio.h>

int pearent(int i){
  return i / 2;
}

int left(int i){
  return 2*i;
}
int right(int i){
  return (2*i)+1;
}

int main(){
  int n,i;
  scanf("%d",&n);
  int a[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(pearent(i) >= 1){
      printf("parent key = %d, ",a[pearent(i)]);
    }

    if(left(i) <= n){
      printf("left key = %d, ",a[left(i)]);
    }

    if(right(i) <= n){
      printf("right key = %d, ",a[right(i)]);
    }
      printf("\n");
  }

  return 0;
}

