#include <stdio.h>
int main(){
  int i,h,H[251],n,I[251];

  for(i=1;i<=250;i++){
    I[i]=-1;
  }

  scanf("%d",&h);

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

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

  return 0;
}