#include<stdio.h>
#define N 250


int main(){

  int T[N],i,n;

  scanf("%d",&n);

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

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

    printf("\n");
  }

  return 0;
}