#include<stdio.h>

int main(){
    int n,i;
    int A[250];
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        scanf("%d",&A[i]);
    }
    for(i=1;i<=n;i++){
        printf("node %d: key = %d, ",i,A[i]);
        if(i!=1)printf("parent key = %d, ",A[i/2]);
        if(2*i<=n)printf("left key = %d, ",A[2*i]);
        if(2*i+1<=n)printf("right key = %d, \n",A[2*i+1]);
        else printf("\n");
    }
}

