#include <stdio.h>
#define MAX 250

/* Global Variable */
int A[MAX+1];

int main() {
  int i, H;

  scanf("%d", &H);
  for ( i = 1; i <= H; i++ ) //1-origin
    scanf("%d", &A[i]);

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

    return 0;
}