#include <stdio.h>
#include <math.h>
#define N 250

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

  return 0;
}

