Problems
Sequences
Sequences
Count the number of all non-decreasing sequences of length $n$ containing integers from $1$ to $m$, where every element can occur at most $k$ times.
\InputFile
Three integers $n, m$ and $k~(0 < n, m, k < 31)$.
\OutputFile
Print the number of described sequences.
\Examples
The sequences are: $(1, 1, 2), (1, 1, 3), (1, 1, 4), (1, 2, 2), (1, 2, 3), (1, 2, 4), (1, 3, 3), (1, 3, 4), (1, 4, 4), (2, 2, 3), (2, 2, 4), (2, 3, 3), (2, 3, 4), (2, 4, 4), (3, 3, 4), (3, 4, 4)$.
Input example #1
3 4 2
Output example #1
16