include <stdio.h>

int main(){
 int i,H,N[251];

  scanf("%d",&H);

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

  for(i = 1; i <= H; i++){
    printf("node %d: key = %d, ",i,N[i]);
    if(i != 1) printf("parent key = %d, ",N[i/2]);
    if(2 * i <= H) printf("left key = %d, ",N[2*i]);
    else{
      printf("\n");
      continue;
    }
    if((2 * i + 1) <= H) printf("right key = %d, ",N[2*i+1]);
      printf("\n");
  }
   return 0;
}
