#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(){
  int loop,i,a[100000];
  scanf("%d",&loop);
  for (i = 1;i <= loop ; i++){
    scanf("%d",&a[i]);
  }
  for (i = 1;i <= loop ;i++){
    printf("node %d: key = %d, ",i,a[i]);
    if(i/2 >= 1) {
      printf("parent key = %d, ",a[i/2]);
    }
    if(2*i <=loop){
      printf("left key = %d, ",a[2*i]);
    }
    if(2*i+1 <= loop){
      printf("right key = %d, ",a[2*i+1]);
    }
    printf("\n");
  }
return 0;
}