#include<stdio.h>
#define MAX 250

int main(){
  int H,i,A[MAX+1];

  scanf("%d",&H);
  for(i=0;i<H;i++){
    scanf("%d",&A[i]);
  }

  for(i=0;i<H;i++){
    printf("node %d: key = %d, ",i+1,A[i]);

    if(i){
      printf("parent key = %d, ",A[(i+1)/2-1]);
    }

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

  return 0;
}

