#include <stdio.h>
#define H 250

int main(){

  int n,i,a[H];
  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&a[i]);
  }

  for(i=1;i<=5;i++) {
    printf("node %d:",i);
    printf(" key = %d",a[i]);
    if(i/2 != 0) {
      printf(" parent key = %d,",a[i/2]);
    }
    if((i*2)<=n) {
      printf(" left key = %d,",a[i*2]);
    }
    if((i*2+1)<=n){
      printf(" right key = %d,",a[i*2+1]);
    }
    printf("\n");
  }
  

  return 0;
}