一道蓝桥杯大水题，按照题意分类模拟即可

#include <iostream>
#include <cstring>
#include <algorithm>
#define intceil(a, b) ((a + b - 1) / b)
using namespace std;
typedef long long LL;

//一周 5 * a + 2 * b
int main()
{
    LL a, b, n;
    scanf("%lld%lld%lld", &a, &b, &n);
    LL ans = n / (5 * a + 2 * b) * 7;
    LL d = n % (5 * a + 2 * b);
    if(d <= 5 * a) {
        ans += intceil(d, a);
    }else {
        ans += 5;
        d -= 5 * a;
        ans += intceil(d, b);
    }
    printf("%lld\n", ans);
    return 0;
}