Factorial

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Time limit1sMemory limit128 MB

Summary

Read n and print the ones digit of n factorial.

Level: Easy1 of 10
Topics: Math, Implementation
Solved: No attempts yet

Problem

Let $n$ be a non-negative integer. The value $n!$ (read " $n$ factorial") is defined as follows. If $n \le 1$ , then $n! = 1$ . If $n > 1$ , then $n!$ is the product of all integers from $1$ to $n$ , that is, $n! = 1 \times 2 \times \cdots \times n$ . For example, $4! = 1 \times 2 \times 3 \times 4 = 24$ .

Write a program that:

reads a non-negative integer $n$ from standard input,
computes the units (ones) digit of $n!$ in its decimal representation,
prints that result to standard output.

Input

The first and only line of standard input contains a single non-negative integer $n$ ( $0 \le n \le 30000$ ).

Output

On the first and only line, print exactly one digit equal to the units digit of $n!$ in its decimal representation.

Examples3

Example 1
Input
```
4
```
Expected output
```
4
```
Example 2
Input
```
0
```
Expected output
```
1
```
Example 3
Input
```
5
```
Expected output
```
0
```