#include<stdio.h>
#define N 250
int A[N];

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

int main(){
  int H;
  int i;

  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(parent(i) >= 1){
      printf("parent key = %d, ",A[parent(i)]);
    }if(left(i) <=H){
      printf("left key = %d, ",A[left(i)]);
    }if(right(i) <= H){
      printf("right key = %d, ",A[right(i)]);
    }
    printf("\n");
  }
  return 0;
}

