include[HTML_REMOVED]
using namespace std;
typedef long long LL;
int main(){
LL a,b,n;
cin>>a>>b>>n;
LL week = a * 5 + b * 2;//一周总共做的题目数
LL day = 0;//做题的天数
//如果剩余的题目大于周一到周五做的总数,需要算b,并加上周一到周五
if (n % week > a * 5) {
//向上取整
if((n % week - 5 * a) % b != 0)
day = (n / week) * 7 + (n % week - 5 * a) / b + 6;
else
day = (n / week) * 7 + (n % week - 5 * a) / b + 5;
}
//如果剩余的题目小于周一到周五做的总数,只用算a
else {
if((n % week) % a != 0)
day = (n / week) * 7 + (n % week) / a + 1;
else
day = (n / week) * 7 + (n % week) / a;
}
cout<<day;
}