A loader has a waggon and a little cart. The waggon can carry up to 1000 kg, and the cart can carry only up to 1 kg.  A finite number of sacks with sand lie in a storehouse. It is known that their total weight is more than 1001 kg, while each sack weighs not more than 1 kg. What maximum weight of sand can the loader carry in the waggon and the cart, regardless of particular weights of sacks? 

[i]Author: M.Ivanov, D.Rostovsky, V.Frank[/i]
1. Let's denote the total weight of the sacks as \( W \). We know that \( W > 1001 \) kg.
2. Each sack weighs at most 1 kg. Therefore, the number of sacks, \( n \), must be at least \( n > 1001 \) since \( W > 1001 \) and each sack weighs at most 1 kg.
3. The waggon can carry up to 1000 kg, and the cart can carry up to 1 kg.
4. To maximize the weight carried by the waggon and the cart, we need to consider the distribution of the sacks between the waggon and the cart.
5. Since each sack weighs at most 1 kg, the waggon can carry at most 1000 sacks, each weighing 1 kg, which sums up to 1000 kg.
6. The cart can carry at most 1 sack, which weighs at most 1 kg.
7. Therefore, the maximum weight that can be carried by the waggon and the cart together is \( 1000 \) kg (waggon) + \( 1 \) kg (cart) = \( 1001 \) kg.
8. Given that the total weight \( W > 1001 \) kg, there will always be at least one sack left behind, regardless of the particular weights of the sacks.

Thus, the maximum weight of sand that the loader can carry in the waggon and the cart is \( 1001 \) kg.

The final answer is \( \boxed{1001} \) kg.