#include<stdio.h>
#define MAX 10000
main(){
  int n, i;
  int x[MAX+1];
  scanf("%d", &n);
  for ( i = 1; i <= n; i++ )
     scanf("%d", &x[i]);

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

    printf("\n");
  }

  return 0;
}
