#include <stdio.h>


int H[251];

int main(){
  int n,i;

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

