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