#include <stdio.h>



int main(){

  int i,n,H[251];
  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)printf("parent key = %d, ",H[i/2]);
    if(i*2<=n)printf("left key = %d, ",H[i*2]);
    if(i*2+1<=n)printf("right key = %d, ",H[i*2+1]);
    printf("\n");
  }
  
  return 0;
}

