#include <stdio.h>

int main()
{

  int A[250];
  int H, i;

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

  return 0;

}


