#include<stdio.h>
#define MAX 250

int main(){
  int n, i;
  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;
}

