#include<stdio.h>
#define MAX 100000

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( 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;
}