#include<stdio.h>
int main(){
    int n,i;
    scanf("%d",&n);
    int a[n+1];
    for(i=1;i<n+1;i++)scanf("%d",&a[i]);

    for(i=1;i<n+1;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",a[2*i+1]);
        printf("\n");
    }
    return 0;
}
