Balls into Boxes

Problem Description

Teacher Yang places $n$ identical balls into $m$ distinct boxes; a box may be empty. How many different ways are there to distribute the balls?

Input Format

One line, two integers $n, m$ ($1 \le n, m \le 10$).

Output Format

One line, one integer: the correct answer to the problem.

Sample Input

7 4

Sample Output

120

Hint

• Topic tag: this problem belongs to the combinatorial counting topic, not a loop exercise — treat it as optional enrichment. Beginners practising loops can safely skip it and come back later.
• Hint: the balls are completely identical — try the "stars and bars" method. The answer is $\binom{n+m-1}{m-1}$ (here $\binom{10}{3} = 120$).