MOD = 10 ** 9 + 7
INF = 10 ** 15

def main():  
    N = int(input())
    ans = 0
    while N > 1:
        if N&1:
            ans += 1
            N += 1
        N >>= 1
        ans += 1
    print(ans)
if __name__ == '__main__':
    main()