#include<stdio.h>
#define N 250

int main(){
  int n,i,x[N];
  scanf("%d",&n);
  for(i=1;i<=n;i++){
    scanf("%d",&x[i]);
  }
  for(i=1;i<=n;i++){
    printf("node %d: key = %d, ",i,x[i]);
    if(i/2>=1){
      printf("parent key = %d, ",x[i/2]);
    }
    if(i*2<=n){
      printf("left key = %d, ",x[i*2]);
    }
    if(i*2+1<=n){
      printf("right key = %d, ",x[i*2+1]);
    }
    printf("\n");
  }
    return 0;
}

