#include <stdio.h>

int heap[251];

int main(void)
{
    int i, n;
    scanf("%d", &n);

    for(i = 1; i <= n; i++)
        scanf("%d", heap + i);

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

        printf("\n");
    }

    return 0;
}