#include <stdio.h>

int main(){
  int n,i,semi[300];

  scanf("%d",&n);

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

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

  return 0;
}

