Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextInt() (int, error) {
	return strconv.Atoi(nextString())
}

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func printArr(arr []string) {
	fmt.Println(strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]"))
}

func main() {
	scanner.Split(bufio.ScanWords)

	coinDaily, _ := nextInt()
	coinWeekly, _ := nextInt()
	coinTarget, _ := nextInt()

	coinCurrent := 0
	i := 0
	for i = 0; i <= 1000000; i++ {
		coinCurrent += coinDaily
		if (i+1)%7 == 0 {
			coinCurrent += coinWeekly
		}
		if coinCurrent >= coinTarget {
			break
		}
	}
	fmt.Println(i + 1)
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<map>
#include<stack>
#include<cmath>
#include<iomanip>
#include<set>
#include<numeric>
#include<sstream>
#include<random>
#include<cassert>
#include<list>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rrep(i, st, n) for (int i = st; i < n; ++i)
using pii = pair<int, int>;
const int inf = 1e9 + 7;
int dy[] = {1, 1, 0, -1, -1, 0};
int dx[] = {1, 0, -1, -1, 0, 1};
#define ceil(a, b) a / b + !!(a % b)

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    int weeks = c / (7 * a + b);
    int days= weeks * 7;
    int coins = days * a + weeks * b;
    int rest = c - coins;
    days += (rest + a - 1) / a;
    cout << days << endl;
}

C++: #include<iostream>
using namespace std;

int main()
{
    int a, b, c, sum=0, login=0, bonus=0;
    cin >> a >> b >> c;
    while(sum < c)
    {
        sum += a;
        login++;
        bonus++;
        if(bonus == 7)
        {
            sum += b;
            bonus = 0;
        }
    }
    cout << login << endl;
}