#include<stdio.h>
#define MAX 250

int main(){

  int i,H,A[MAX],n=0;

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

  for(i=1;i<=H;i++){

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

  return 0;
}