#include<stdio.h>

int main()
{
  int H,i,A[100001];//１オリジンだから＋１

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

  for(i=1;i<=H;i++){
    printf("node %d: key = %d, ",i,A[i]);
    if( i/2 >= 1 ) 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;
}

