#include<stdio.h>
#define MAX 100001

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

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

