#include<stdio.h>
#define max 250

int main(){
  int n,i;
  int a[max];
  
  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/2>=1) 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;
}

