n=int(input("请输入n："))
day=0
ti=0
a=int(input("请输入a:"))
b=int(input("请输入b:"))
for i in range(n):
    day+=1
    if day%7<=5 and day%7>0:
        ti+=a
    elif day%7==0 or day%7==6:
        ti+=b
    if ti>=n:
        print(day)
        break