#This program finds the next closest prime number (lower or higher)


def find_next_prime(n):
    #flag = 0 means that the number found is prime
    #flag = 1 means that the number found is composite (has factors)


    if n <= 1: #in the case n is negative, 0 or 1, closest prime number is always 2
        closestprime = 2
    else:
        for i in reversed(range (2, n)): #looking for closest lower prime number, saved as lowp:
            flag = 0
            for a in range (2, i): #tests if i is a prime number
                attempt = i % a
                if attempt == 0: #factor found, i not prime
                    flag = 1
                    break
            if flag == 0: #went through for loop and found that i is prime
                lowp = i
                break
        flag = 1
        test = n
        while flag == 1:#find closest higher prime, saved as highp:
            test = test + 1
            flag = 0 #assume this test is prime
            for i in range (2, test): #Check if test is really prime
                attempt = test % i
                if attempt == 0: #test is not a prime number
                    flag = 1
                    break #try next number

            if flag == 0: #n is actually a prime number!
                highp = test

        if (n - lowp) > (highp - n):
            closestprime = highp

        elif (n - lowp) < (highp - n):
            closestprime = lowp

        elif (n - lowp) == (highp - n):
            return "The number " + str(n) + " is equally close to the prime numbers " + str(lowp) + " and " + str(highp)

    return closestprime