#include <stdio.h>
#define MAX 250

int main(){

    int n;
    int i;
    scanf("%d",&n);
    int H[MAX];

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

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

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

        if( 2*i <= n ){
            printf("left key = %d, ",H[2*i]);
        }

        if( 2*i+1 <= n ){
            printf("right key = %d, ",H[2*i+1]);
        }

        printf("\n");
    }


    return 0;
}