#include<stdio.h>

#define MAX 250

int main(){
  int H,i,A[MAX+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;
}

