#include<stdio.h>

int main(){
  int A[250];
  int i,j,n;

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

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

