#include <stdio.h>

int main(){
  int a[251],h,i;
  scanf("%d",&h);
  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/2!=0) printf("parent key = %d, ",a[i/2]);
    if(h>=2*i) printf("left key = %d, ",a[i*2]);
    if(h>=2*i+1) printf("right key = %d, ",a[i*2+1]);
    printf("\n");
  }
  return 0;
}
  

