#include<stdio.h>
#define MAX 250

int main(){
    int n,i,a[MAX];

    scanf("%d" ,&n);
    for(i=0; i<n; i++){
        scanf("%d" , &a[i]);
    }

    for(i=0; i<n; i++){
        printf("node %d: key = %d, " ,i+1 ,a[i]);

        if(i){
            printf("parent key = %d, " ,a[(i+1)/2-1]);
        }

        if(2*i+1 < n){
            printf("left key = %d " ,a[2*i+1]);
        }
        if(2*i+2 < n){
            printf("right key = %d, " ,a[2*i+2]);
        }
        printf("\n");
    }
    return 0;
}
