#include <stdio.h>
#include <stdlib.h>

int main(void){
    int H,i,*A;
    scanf("%d",&H);
    A=malloc(sizeof(int)*(H+1));
    for(i=1;i<=H;i++)
        scanf("%d",A+i);

    for(i=1;i<=H;i++){
        printf("node %d: key = %d, ",i,A[i]);
        if(i/2>0) printf("parent key = %d, ",A[i/2]);
        if(2*i<=H) printf("left key = %d, ",A[2*i]);
        if(2*i<H) printf("right key = %d, ",A[2*i+1]);
        printf("\n");
    }
    
    return 0;
}
