#include <stdio.h>

int main(){
  int h,i;
  scanf("%d",&h);

  int a[h+1];

  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==1){
      printf("left key = %d, right key = %d, ",a[i*2],a[i*2+1]);
    }
    else {
      printf("parent key = %d, ",a[i/2]);

      if(i*2<=h){
	printf("left key = %d, ",a[i*2]);
      }

      if(i*2+1<=h){
	printf("right key = %d, ",a[i*2+1]);
      }
    }
    printf("\n");
  }
      
	
  return 0;
}

