#include <stdio.h>
#define H 250

typedef struct{
  int k;
  int l;
  int r;
  int p;
}Node;

Node A[H];

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

int main(){
  int n,i;

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

  for(i=1;i<=n;i++){
    if(i/2>=1){
      A[i].p=A[i/2].k;
    }
    if(left(i)<=n){
      A[i].l=A[left(i)].k;
    }
    if(right(i)<=n){
      A[i].r=A[right(i)].k;
    }

    printf("node %d: key = %d, ",i,A[i].k);

    if(A[i].p){
      printf("parent key = %d, ",A[i].p);
    }
    if(A[i].l){
      printf("left key = %d, ",A[i].l);
    }
    if(A[i].r){
      printf("right key = %d, ",A[i].r);
    }

    printf("\n");
  }
  
  return 0;
}

