#define MAX 100000

int parent (int i)
{
return i/2;
}

int left (int i)
{
return 2*i;
}

int right (int i)
{
return 2*i+1;
}

int main()
{
int n, i, a[MAX+1];

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(parent(i) >= 1)
printf("parent key = %d, ", a[parent(i)]);
if(left(i) <= n)
printf("left key = %d, ", a[left(i)]);
if(right(i) <= n)
printf("right key = %d, ", a[right(i)]);
printf("?\n");
}
return 0;
}