#include <stdio.h>
#define MAX 251

int main(){
  int i,H,A[MAX];

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

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

  return 0;
}