mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    N = int(input())

    dp = [10 ** 9] * (N+1)
    dp[1] = 0
    for i in range(1, N):
        for j in range(2, N+1):
            if i * j > N:
                break
            dp[i * j] = min(dp[i * j], dp[i] + j)
    print(dp[N])


if __name__ == '__main__':
    main()