#include <stdio.h>
int main(){
  int H[251];
  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 >= 1 && i/2 <= n)printf("parent key = %d, ",H[i/2]);
    if(i*2 >= 1 && i*2 <= n)printf("left key = %d, ",H[i*2]);
    if(i*2+1 >= 1 && i*2+1 <= n)printf("right key = %d, ",H[i*2+1]);
    printf("\n");
  }
  return 0;
}

