#include<stdio.h>
int main(void)
{
    int heaps[251],H,i;
    scanf("%d",&H);
    for(i=1;i<=H;i++) scanf("%d" ,&heaps[i]);
    for(i=1;i<=H;i++){
        printf("node %d: key = %d, ",i,heaps[i]);
        if(i!=1) printf("parent key = %d, ",heaps[i/2]);
        if(i*2<=H) printf("left key = %d, ",heaps[i*2]);
        if(i*2+1<=H) printf("right key = %d, ",heaps[i*2+1]);
        printf("\n");
    }
    return 0;
}