#include<stdio.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 H,i,A[MAX+1];

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

    for(i = 1; i <= H; i++){
        printf("node %d: key = %d, ",i,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;
}
