#include<stdio.h>
#include<stdlib.h>

#define MAX 100000

int parent(int i) {return i / 2;}
int left(int i) {return 2*i;}
int right(int i){return 2*i + 1;}

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: ", i);
        printf("key = %d, ", A[i]);
        if(parent(i) >= 1) printf("parent key = %d, ", A[parent(i)]);
        if(left(i) <= h) printf("left key = %d, ", A[left(i)]);
        if(right(i) <= h) printf("right key = %d, ", A[right(i)]);
        printf("\n");
    }

    return 0;
}
