def make_divisors(n):
    lower_divisors , upper_divisors = [], []
    i = 1
    while i*i <= n:
        if n % i == 0:
            lower_divisors.append(i)
            if i != n // i:
                upper_divisors.append(n//i)
        i += 1
    return lower_divisors + upper_divisors[::-1]
    
N = int(input())
dp = [1 << 60] * (N + 1)
dp[1] = 0
for i in range(1, N + 1):
    for k in range(2, N + 1):
        if i * k > N:
            break
        dp[i * k] = min(dp[i * k], dp[i] + k)
        
print(dp[N])