#include<stdio.h>
#define heap_max 250
     
int main(){
    int i,heap[heap_max],inHeap;
     
    scanf("%d",&inHeap);
    for(i=1;i<inHeap+1;i++) scanf("%d",&heap[i]);
     
    for(i=1;i<inHeap+1;i++){
        printf("node %d: key = %d,",i+1,heap[i]);
        if(i/2!=0) printf(" parent key = %d,",heap[i/2]);
        if(2*i<=inHeap) printf(" left key = %d,",heap[2*i]);
        if((2*i+1)<=inHeap) printf(" right key = %d,",heap[2*i+1]);
        printf(" \n");
        }
    return 0;
    }