#include <stdio.h>
#define MAX 251

int main(){

  int a[MAX];
  int i,n;

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

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

  return 0;
}