#include <stdio.h>

int main(){
  int i,n,H[251];

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

  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,H[i]);
    if(i!=1)printf("parent key = %d, ",H[i/2]);
    if(2*i>n&&2*i+1>n){
      printf("\n");
      continue;
    }
    else if(2*i+1>n){
      printf("left key = %d, \n",H[2*i]);
      continue;
    }
    else printf("left key = %d, right key = %d, ",H[2*i],H[2*i+1]);
    printf("\n");
  }
  return 0;
}