import sys
import math

def main():
    text = sys.stdin.readline()
    bisckets_n =  int(text)
    bisckets_ini = 1
    bisckets_total = 0
    tap_count = 0
    tap_total = 0
    
    while (bisckets_n - bisckets_total) > 1:
        tap_count = math.floor((math.log10(bisckets_n - bisckets_total) - math.log10(bisckets_ini)) / math.log10(2))
        bisckets_total += pow(bisckets_ini * 2,tap_count)
        if (bisckets_n - bisckets_total) == 1 :
            bisckets_ini = 1.0
        else:
            bisckets_ini = math.floor((bisckets_n - bisckets_total) / 2)
        tap_total +=  tap_count
        #print("tap:" + str(tap_count),"total biskets:" + str(bisckets_total),"next biskets:" + str(bisckets_ini))
        
    print(tap_total)
    
if __name__ == "__main__":
    main()