5. Determine the number of ways to represent a natural number $n$ as the sum of several (two or more) natural numbers, where the order matters. (For example, for $n=4$, we have the following possibilities: $3+1, 2+2, 1+3, 2+1+1$, $1+2+1, 1+1+2, 1+1+1+1$, i.e., a total of 7 desired ways.)

## Fourth grade - B category