#include<stdio.h>
#define M 100000

int parent(int);
int left(int );
int right(int);

int main(void){
  int n,A[M+1],i;

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

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

}

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

