N = int(input())

bisc = 1
power = 0

if bisc == 1:
    print(power)
    exit()

while True:
    if bisc * 2 == N:
        power += 1
        print(power)
        break
    else:
        if N - bisc * 2 < 0:
            power += 1
            print(power)
            break
        else:
            bisc *= 2
            power += 1