Get the next prime number!

You will get a number`n` (>= 0) and your task is to find the next prime number. 

Make sure to optimize your code: there will numbers tested up to about `10^12`.

## Examples

```
5   =>  7
12  =>  13
```

Source: codewars | Difficulty: EASY

Starter code: def is_prime(n):
	

Solutions:
from itertools import count

def is_prime(n):
	if n < 2:
		return False
	if n == 2:
		return True
	if n % 2 == 0:
		return False
	for div in range(2, int(n ** 0.5) + 1):
		if n % div == 0:
			return False
	return True

def next_prime(n):
	for candidate in count(n + 1):
		if is_prime(candidate):
			return candidate


def is_prime(n):
	for i in range(2, int(n ** 0.5) + 1):
		if n % i == 0:
			return False
	return n > 1

def next_prime(n):
	i = n + 1
	while not is_prime(i):
		i += 1
	return i


def is_prime(n):
	if n in (2, 3, 5):
		return True
	elif n < 5:
		return False
	elif n % 2:
		i = 3
		flag = True
		while i * i <= n:
			if n % i == 0:
				return False
			i += 2
		return True
	else:
		return False

def nextPrime(n):
	i = n + 1
	while not is_prime(i):
		i += 1
	return i