JavaScriptEasyNumbers10 min

Compute a factorial

Compute n factorial, with 0 factorial defined as 1. All input is valid JSON satisfying the constraints; do not mutate the meaning of values through type coercion. Interviewers use this problem to assess accumulate the product iteratively.

Input

A JSON integer n.

Output

Print one compact JSON value: an integer.

Constraints

0 <= n <= 18; all results are exact JavaScript integers.

Example

Input

Output

Example 2 input

Output

Boundary case: Zero factorial is one

Public test cases (2)

Input
```
5
```
Expected output
```
120
```
Input
```
3
```
Expected output
```
6
```

Hints (2)

Start the product at one
Zero factorial is one

Target complexity: time O(n) · space O(1)

Your solution

const input = JSON.parse(require("fs").readFileSync(0, "utf8"));
function solve(input) {
  // your code
  return 0;
}
console.log(JSON.stringify(solve(input)));

Standard input

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Reference solution

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All JavaScript programs

Compute a factorial

Input

Output

Constraints

Example

Public test cases (2)

Your solution

Reference solution

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