#include <stdio.h>

#define N 250

int main(){
  int n,i,a[N+1];
  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){
      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;
}

