#include<stdio.h>

int main(){
  int H, i, key[250];
  scanf("%d", &H);
  for(i = 1 ; i <= H ; i++) scanf("%d", &key[i]);

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

