python

while True:
    try:
        N = int(input())
        seven_list=[]
        for i in range(1,N+1):
            if '7' in str(i):
                seven_list.append(i)
            else:
                if i%7==0:
                    seven_list.append(i)
        output=len(seven_list)
        print(output)
    except:
        break