#include<stdio.h>
#define MAX 100000

int main( ){
  int i,j,n;
  int A[MAX+1];

  scanf("%d",&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(i/2>=1){
      printf("parent key = %d, ",A[i/2]);
    }
    if(i * 2 <= n){
      printf("left key = %d, ",A[i*2]);
    }
    if(i*2+1 <= n){
      printf("right key = %d, ",A[i*2+1]);
    }
      printf("\n");
    
  }
    return 0;
  }

