#include <stdio.h>
#define MAX 250
int parent(int );
int left(int );
int right(int );



int main(){
  int i;
  int n;
  int H[MAX+1];

  scanf("%d",&n);

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

  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,H[i]);
    if(parent(i) >= 1 )printf("parent key = %d, ",H[parent(i)] );
    if(left(i) <= n )printf("left key = %d, ",H[left(i)] );
    if(right(i) <= n )printf("right key = %d, ",H[right(i)] );
    printf("\n");
  }

  
  return 0;
}


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

int left(int i){
  return i*2;
}

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

